Retro/pcjs
Watch
1
0
Fork
You've already forked pcjs
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
pcjs/modules/pcjs/lib/video.js
Jeff Parsons 87d01130bd Make the PC8080 prototype page more responsive
2016-04-20 16:43:01 -07:00

7370 lines
324 KiB
JavaScript
Raw Blame History

/**
* @fileoverview Implements the PCjs Video component.
* @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
* @version 1.0
* Created 2012-Jun-15
*
* Copyright © 2012-2016 Jeff Parsons <Jeff@pcjs.org>
*
* This file is part of PCjs, which is part of the JavaScript Machines Project (aka JSMachines)
* at <http://jsmachines.net/> and <http://pcjs.org/>.
*
* PCjs is free software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* PCjs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with PCjs. If not,
* see <http://www.gnu.org/licenses/gpl.html>.
*
* You are required to include the above copyright notice in every source code file of every
* copy or modified version of this work, and to display that copyright notice on every screen
* that loads or runs any version of this software (see Computer.COPYRIGHT).
*
* Some PCjs files also attempt to load external resource files, such as character-image files,
* ROM files, and disk image files. Those external resource files are not considered part of the
* PCjs program for purposes of the GNU General Public License, and the author does not claim
* any copyright as to their contents.
*/
"use strict";
if (NODE) {
var str = require("../../shared/lib/strlib");
var web = require("../../shared/lib/weblib");
var DumpAPI = require("../../shared/lib/dumpapi");
var Component = require("../../shared/lib/component");
var Memory = require("./memory");
var Messages = require("./messages");
var ChipSet = require("./chipset");
var Keyboard = require("./keyboard");
var Mouse = require("./mouse");
var State = require("./state");
}
/**
* Video(parmsVideo, canvas, context, textarea, container)
*
* The Video component can be configured with the following (parmsVideo) properties:
*
* model: model (eg, "mda" for Monochrome Display Adapter)
* mode: initial video mode (default is null, which selects a mode based on model)
* memory: amount of installed memory (ignored for MDA/CGA)
* screenWidth: width of the screen canvas, in pixels
* screenHeight: height of the screen canvas, in pixels
* scale: true for font scaling, false (default) to center the display on the screen
* charCols: number of character columns
* charRows: number of character rows
* fontROM: path to .rom file (or a JSON representation) containing the character set
* screenColor: background color of the screen canvas (default is black)
* touchScreen: string specifying desired touch-screen support (default is none)
* autoLock: true to (attempt to) auto-lock the mouse to the canvas (default is false)
*
* An EGA may specify the following additional properties:
*
* switches: string representing EGA switches (see "SW1-SW4" documentation below)
* memory: the size of the EGA's on-board memory (overrides EGA's Video.cardSpecs)
*
* This calls the Bus to allocate a video buffer at the appropriate memory location whenever
* a reset() or setMode() occurs; setMode() is called whenever a mode change is detected at
* the port level, and whenever reset() is called. setMode() also invokes updateScreen(true),
* which forces reallocation of our internal buffer (aCellCache) that mirrors the video buffer.
*
* The CPU periodically calls updateVideo(), which in turn calls updateScreen() for each Video
* instance. These updates should occur at a rate of 60 times/second, to update any blinking
* elements (the cursor and any cells with the blink attribute), to compare/update the contents
* of our internal buffer with the video buffer, and to render any differences between the two
* buffers into the associated screen canvas, via either updateChar() or setPixel().
*
* Thanks to the Bus' new block-based memory manager that allows us to sparse-allocate memory
* (in 4Kb increments on 20-bit buses, 16Kb increments on 24-bit buses), updateScreen()
* can also ask the CPU for the "dirty" state of all the blocks underlying the video buffer,
* bypassing the update completely if the buffer is still clean.
*
* Sadly, that optimization is defeated if the count of active blink elements is non-zero,
* because we must rescan the entire buffer to locate and redraw them all; I'm assuming for now
* that, more often than not, very few (if any) blink attributes will be present, and therefore
* they're not worth a separate caching mechanism. If the only blinking element is the cursor,
* that's no problem, as we redraw only the one cell containing the cursor (assuming the buffer
* is otherwise clean).
*
* @constructor
* @extends Component
* @param {Object} parmsVideo
* @param {Object} [canvas]
* @param {Object} [context]
* @param {Object} [textarea]
* @param {Object} [container]
*/
function Video(parmsVideo, canvas, context, textarea, container)
{
Component.call(this, "Video", parmsVideo, Video, Messages.VIDEO);
/*
* This records the model specified (eg, "mda", "cga", "ega", "vga" or "" if none specified);
* when a model is specified, it overrides whatever model we infer from the ChipSet's switches
* (since those motherboard switches tell us only the type of monitor, not the type of card).
*/
this.model = parmsVideo['model'];
var aModelDefaults = Video.MODEL[this.model] || Video.MODEL['mda'];
this.nCard = aModelDefaults[0];
this.cbMemory = parmsVideo['memory'] || 0; // zero means fallback to the cardSpec's default size
this.sSwitches = parmsVideo['switches'];
/*
* powerUp() uses the default mode ONLY if ChipSet doesn't give us a default.
*/
this.nModeDefault = parmsVideo['mode'];
if (this.nModeDefault == null || Video.aModeParms[this.nModeDefault] == null) {
this.nModeDefault = aModelDefaults[1];
}
/*
* setDimensions() uses these values ONLY if it doesn't recognize the video mode.
*/
this.nColsDefault = parmsVideo['charCols'];
this.nRowsDefault = parmsVideo['charRows'];
if (this.nColsDefault === undefined || this.nRowsDefault === undefined) {
this.nColsDefault = Video.aModeParms[this.nModeDefault][0];
this.nRowsDefault = Video.aModeParms[this.nModeDefault][1];
}
/*
* setDimensions() uses these values unconditionally, as the machine has no idea what the
* physical screen size should be.
*/
this.cxScreen = parmsVideo['screenWidth'];
this.cyScreen = parmsVideo['screenHeight'];
/*
* We might consider another component parameter to specify the font-doubling setting.
* For now, it's based on whether the default SCREEN cell size is sufficiently larger than
* the default FONT cell size.
*/
this.fScaleFont = parmsVideo['scale'];
this.fDoubleFont = Math.round(this.cxScreen / this.nColsDefault) >= 12;
this.canvasScreen = canvas;
this.contextScreen = context;
this.textareaScreen = textarea;
this.inputScreen = textarea || canvas || null;
/*
* initBus() will determine touch-screen support; for now, just record values and set defaults.
*/
this.sTouchScreen = parmsVideo['touchScreen'];
this.nTouchConfig = Video.TOUCH.NONE;
/*
* If a Mouse exists, we'll be notified when it requests our canvas, and we make a note of it
* so that if lockPointer() is ever invoked, we can notify the Mouse.
*/
this.mouse = null;
this.fAutoLock = parmsVideo['autoLock'];
/*
* Originally, setMode() would map/unmap the video buffer ONLY when the active card changed,
* because as long as an MDA or CGA remained active, its video buffer never changed. However,
* since the EGA can change its video buffer on the fly, setMode() must also compare the card's
* hard-coded and/or programmed buffer address/size to the "active" address/size; the latter
* is recorded here.
*/
this.addrBuffer = this.sizeBuffer = 0;
/*
* aFonts is an array of font objects indexed by FONT ID. Font characters are arranged
* in 16x16 grids, with one grid per canvas object in the aCanvas array of each font object.
*
* Each element is a Font object that describes the font size and provides bitmaps for all the font
* color permutations. aFonts.length will be non-zero if ANY fonts are loaded, but do NOT assume
* that EVERY font has been loaded; check for the existence of a font by checking for its unique ID
* within this sparse array.
*/
this.aFonts = [];
/*
* Instead of (re)allocating a new color array every time getCardColors() is called, we preallocate
* an array and simply update the entries as needed. Note that for an EGA (or a VGA operating in an
* EGA-compatible mode), only the first 16 entries get used (derived from the ATC); only when a VGA
* is operating in an 8bpp mode are 256 entries used (derived from the DAC rather than the ATC).
*/
this.aRGB = new Array(this.nCard == Video.CARD.VGA? 256 : 16);
this.fRGBValid = false; // whenever this is false, it signals getCardColors() to rebuild aRGB
/*
* Since I've not found clear documentation on a reliable way to check whether a particular DOM element
* (other than the BODY element) has focus at any given time, I've added onfocus() and onblur() handlers
* to the screen to maintain my own focus state.
*/
this.fHasFocus = false;
/*
* Here's the gross code to handle full-screen support across all supported browsers. The lack of standards
* is exasperating; browsers can't agree on 'full' or 'Full, 'request' or 'Request', 'screen' or 'Screen', and
* while some browsers honor other browser prefixes, most browsers don't.
*/
var video = this;
this.fGecko = web.isUserAgent("Gecko/");
var i, sEvent, asPrefixes = ['', 'moz', 'webkit', 'ms'];
this.container = container;
if (this.container) {
this.container.doFullScreen = container['requestFullscreen'] || container['msRequestFullscreen'] || container['mozRequestFullScreen'] || container['webkitRequestFullscreen'];
if (this.container.doFullScreen) {
for (i = 0; i < asPrefixes.length; i++) {
sEvent = asPrefixes[i] + 'fullscreenchange';
if ('on' + sEvent in document) {
var onFullScreenChange = function() {
var fFullScreen = (document['fullscreenElement'] || document['mozFullScreenElement'] || document['webkitFullscreenElement'] || document['msFullscreenElement']);
video.notifyFullScreen(fFullScreen? true : false);
};
document.addEventListener(sEvent, onFullScreenChange, false);
break;
}
}
for (i = 0; i < asPrefixes.length; i++) {
sEvent = asPrefixes[i] + 'fullscreenerror';
if ('on' + sEvent in document) {
var onFullScreenError = function() {
video.notifyFullScreen(null);
};
document.addEventListener(sEvent, onFullScreenError, false);
break;
}
}
}
}
/*
* More gross code to handle pointer-locking support across all supported browsers.
*
* TODO: Consider "upgrading" this code to use the same asPrefixes array as above, especially once Microsoft
* finally releases a browser that supports pointer-locking (post-Windows 10?)
*/
if (this.inputScreen) {
this.inputScreen.onfocus = function onFocusScreen() {
return video.onFocusChange(true);
};
this.inputScreen.onblur = function onBlurScreen() {
return video.onFocusChange(false);
};
this.inputScreen.lockPointer = this.inputScreen['requestPointerLock'] || this.inputScreen['mozRequestPointerLock'] || this.inputScreen['webkitRequestPointerLock'];
this.inputScreen.unlockPointer = this.inputScreen['exitPointerLock'] || this.inputScreen['mozExitPointerLock'] || this.inputScreen['webkitExitPointerLock'];
if (this.inputScreen.lockPointer) {
var onPointerLockChange = function() {
var fLocked = (
document['pointerLockElement'] === video.inputScreen ||
document['mozPointerLockElement'] === video.inputScreen ||
document['webkitPointerLockElement'] === video.inputScreen);
video.notifyPointerLocked(fLocked);
};
if ('onpointerlockchange' in document) {
document.addEventListener('pointerlockchange', onPointerLockChange, false);
} else if ('onmozpointerlockchange' in document) {
document.addEventListener('mozpointerlockchange', onPointerLockChange, false);
} else if ('onwebkitpointerlockchange' in document) {
document.addEventListener('webkitpointerlockchange', onPointerLockChange, false);
}
}
}
/*
* As far as overall image quality of scaled fonts, these options don't seem necessary for Safari (and
* don't have any discernible effect anyway). Turning 'webkitImageSmoothingEnabled' off DOES have an effect
* on Chrome, but it's not really a positive effect overall, so I'm leaving these off for now.
*
* if (this.contextScreen) {
* this.contextScreen['mozImageSmoothingEnabled'] = false;
* this.contextScreen['webkitImageSmoothingEnabled'] = false;
* }
*/
var sFileURL = parmsVideo['fontROM'];
if (sFileURL) {
var sFileExt = str.getExtension(sFileURL);
if (sFileExt != "json") {
sFileURL = web.getHost() + DumpAPI.ENDPOINT + '?' + DumpAPI.QUERY.FILE + '=' + sFileURL + '&' + DumpAPI.QUERY.FORMAT + '=' + DumpAPI.FORMAT.BYTES;
}
web.getResource(sFileURL, null, true, function(sURL, sResponse, nErrorCode) {
video.doneLoad(sURL, sResponse, nErrorCode);
});
}
}
Component.subclass(Video);
Video.TRAPALL = true; // monitor all I/O by default (not just deltas)
/*
* MDA/CGA Support
*
* Since there's a lot of similarity between the MDA and CGA (eg, their text-mode video buffer
* format, and their use of the 6845 CRT controller), since the MDA ROM contains the fonts used
* by both devices, and since the same ROM BIOS supports both (in fact, the BIOS indiscriminately
* initializes both, regardless which is actually installed), this same component emulates both
* devices.
*
* When no model is specified, this component supports the ability to dynamically switch between
* MDA and CGA emulation, by simply toggling the SW1 motherboard "monitor type" switch settings
* and resetting the machine. In that model-less configuration, we install I/O port handlers for
* both MDA and CGA cards, regardless which monitor type is initially selected.
*
* To simulate an IBM PC containing both an MDA and CGA (ie, a "dual display" system), the machine
* configuration simply defines two video components, one with model "mda" and the other with model
* "cga", resulting in two displays; setting a specific model forces each instance of this component
* to register only those I/O ports belonging to that model.
*
* In a single-display system, dynamically switching cards (ie, between MDA and CGA) creates some
* visual challenges. For one, the MDA prefers a native screen size of 720x350, as it supports only
* one video mode, 80x25, with a 9x14 cell size. The CGA, on the other hand, has an 8x8 cell size,
* so when using an MDA-size screen, an 80x25 CGA screen will end up with 40-pixel borders on the
* left and right, and 75-pixel borders on the top and bottom. The result is a rather tiny CGA font
* surrounded by lots of wasted space, so it's best to turn on font scaling (see the "scale" property)
* and go with a larger screen size of, say, 960x400 (50% larger in width, 100% larger in height).
*
* I've also added support for font-doubling in createFont(). We use the 8x8 font for 80-column
* modes and the "doubled" 16x16 font for 40-column modes OR whenever the screen is large enough
* to use the 16x16 font, since font rendering without scaling provides the sharpest results.
* In fact, there's special logic in setDimensions() to ignore fScaleFont in certain cases (eg,
* 40-column modes, to improve sharpness and avoid stretching the font beyond readability).
*
* Graphics modes, on the other hand, are always scaled to the screen size. Pixels are captured
* in an off-screen buffer, which is then drawn to match the size of the virtual screen.
*
* TODO: Whenever there are borders, they should be filled with the CGA's overscan colors. However,
* in the case of graphics modes (and text modes whenever font scaling is enabled), we don't reserve
* any space for borders, so if borders are important, explicit border support will be required.
*/
/*
* EGA Support
*
* EGA support piggy-backs on the existing MDA/CGA support. All the existing MDA/CGA port handlers
* now refer to either cardMono or cardColor (instead of directly to cardMDA or cardCGA), enabling
* the handlers to be redirected to cardMDA, cardCGA or cardEGA as appropriate.
*
* Note that an MDA card supported only a Monochrome Display and a CGA card supported only a Color
* Display (well, OK, *or* a TV monitor, which we don't currently support), but the EGA is much
* more flexible: the Enhanced Color Display was the preferred display, but the EGA also supported
* older displays; a Color Display on EGA wasn't ideal (same low resolutions but with more colors),
* but the EGA also brought high-resolution graphics to Monochrome displays, which was nice. Anyway,
* while all those EGA/monitor combinations will be nice to support, our virtual display support
* will focus initially on the Enhanced Color Display.
*
* TODO: Add support for jumpers P1 and P3 (see EGA TechRef p.85). P1 selects either 5-color-output
* for a CGA monitor or 6-color-output for an EGA monitor; we would presumably use this only to
* control certain assumptions about the virtual display's capabilities (ie, Color Display vs. Enhanced
* Color Display). P3 can switch all the I/O ports from 0x3nn to 0x2nn; the default is 0x3nn, and
* that's the only port range the EGA ROM supports as well.
*/
/*
* VGA Support
*
* More will be said here about PCjs VGA support later. But first, a word from IBM: "Video Graphics Array [VGA]
* Programming Considerations":
*
* Certain internal timings must be guaranteed by the user, in order to have the CRTC perform properly.
* This is due to the physical design of the chip. These timings can be guaranteed by ensuring that the
* rules listed below are followed when programming the CRTC.
*
* 1. The Horizontal Total [HTOTAL] register (R0) must be greater than or equal to a value of
* 25 decimal.
*
* 2. The minimum positive pulse width of the HSYNC output must be four character clock units.
*
* 3. Register R5, Horizontal Sync End [HRETRACE_END], must be programmed such that the HSYNC
* output goes to a logic 0 a minimum of one character clock time before the 'horizontal display enable'
* signal goes to a logical 1.
*
* 4. Register R16, Vsync Start [VRETRACE_START], must be a minimum of one horizontal scan line greater
* than register R18 [VDISP_END]. Register R18 defines where the 'vertical display enable' signal ends.
*
* When bit 5 of the Attribute Mode Control register equals 1, a successful line compare (see Line Compare
* [LINE_COMPARE] register) in the CRT Controller forces the output of the PEL Panning register to 0's until Vsync
* occurs. When Vsync occurs, the output returns to the programmed value. This allows the portion of the screen
* indicated by the Line Compare register to be operated on by the PEL Panning register.
*
* A write to the Character Map Select register becomes valid on the next whole character line. No deformed
* characters are displayed by changing character generators in the middle of a character scan line.
*
* For 256-color 320 x 200 graphics mode hex 13, the attribute controller is configured so that the 8-bit attribute
* stored in video memory for each PEL becomes the 8-bit address (P0 - P7) into the integrated DAC. The user should
* not modify the contents of the internal Palette registers when using this mode.
*
* The following sequence should be followed when accessing any of the Attribute Data registers pointed to by the
* Attribute Index register:
*
* 1. Disable interrupts
* 2. Reset read/write flip/flop
* 3. Write to Index register
* 4. Read from or write to a data register
* 5. Enable interrupts
*
* The Color Select register in the Attribute Controller section may be used to rapidly switch between sets of colors
* in the video DAC. When bit 7 of the Attribute Mode Control register equals 0, the 8-bit color value presented to the
* video DAC is composed of 6 bits from the internal Palette registers and bits 2 and 3 from the Color Select register.
* When bit 7 of the Attribute Mode Control register equals 1, the 8-bit color value presented to the video DAC is
* composed of the lower four bits from the internal Palette registers and the four bits in the Color Select register.
* By changing the value in the Color Select register, software rapidly switches between sets of colors in the video DAC.
* Note that BIOS does not support multiple sets of colors in the video DAC. The user must load these colors if this
* function is to be used. Also see the Attribute Controller block diagram on page 4-26. Note that the above discussion
* applies to all modes except 256 Color Graphics mode. In this mode the Color Select register is not used to switch
* between sets of colors.
*
* An application that saves the "Video State" must store the 4 bytes of information contained in the system microprocessor
* latches in the graphics controller subsection. These latches are loaded with 32 bits from video memory (8 bits per map)
* each time the system microprocessor does a read from video memory. The application needs to:
*
* 1. Use write mode 1 to write the values in the latches to a location in video memory that is not part of
* the display buffer. The last location in the address range is a good choice.
*
* 2. Save the values of the latches by reading them back from video memory.
*
* Note: If in a chain 4 or odd/even mode, it will be necessary to reconfigure the memory organization as four
* sequential maps prior to performing the sequence above. BIOS provides support for completely saving and
* restoring video state. See the IBM Personal System/2 and Personal Computer BIOS Interface Technical Reference
* for more information.
*
* The description of the Horizontal PEL Panning register includes a figure showing the number of PELs shifted left
* for each valid value of the PEL Panning register and each valid video mode. Further panning beyond that shown in
* the figure may be accomplished by changing the start address in the CRT Controller registers, Start Address High
* and Start Address Low. The sequence involved in further panning would be as follows:
*
* 1. Use the PEL Panning register to shift the maximum number of bits to the left. See Figure 4-103 on page
* 4-106 for the appropriate values.
*
* 2. Increment the start address.
*
* 3. If you are not using Modes 0 + , 1 + , 2 + , 3 + ,7, or7 + , set the PEL Panning register to 0. If you
* are using these modes, set the PEL Panning register to 8. The screen will now be shifted one PEL left
* of the position it was in at the end of step 1. Step 1 through Step 3 may be repeated as desired.
*
* The Line Compare register (CRTC register hex 18) should be programmed with even values in 200 line modes when
* used in split screen applications that scroll a second screen on top of a first screen. This is a requirement
* imposed by the scan doubling logic in the CRTC.
*
* If the Cursor Start register (CRTC register hex 0A) is programmed with a value greater than that in the Cursor End
* register (CRTC register hex 0B), then no cursor is displayed. A split cursor is not possible.
*
* In 8-dot character modes, the underline attribute produces a solid line across adjacent characters, as in the IBM
* Color/Graphics Monitor Adapter, Monochrome Display Adapter and the Enhanced Graphics Adapter. In 9-dot modes, the
* underline across adjacent characters is dashed, as in the IBM 327X display terminals. In 9-dot modes, the line
* graphics characters (C0 - DF character codes) have solid underlines.
*
* For compatibility with the IBM Enhanced Graphics Adapter (EGA), the internal VGA palette is programmed the same
* as the EGA. The video DAC is programmed by BIOS so that the compatible values in the internal VGA palette produce
* a color compatible with what was produced by EGA. Mode hex 13 (256 colors) is programmed so that the first 16
* locations in the DAC produce compatible colors.
*
* Summing: When BIOS is used to load the video DAC palette for a color mode and a monochrome display is connected
* to the system unit, the color palette is changed. The colors are summed to produce shades of gray that allow
* color applications to produce a readable screen.
*
* There are 4 bits that should not be modified unless the sequencer is reset by setting bit 1 of the Reset register
* to 0. These bits are:
*
* • Bit 3, or bit 0 of the Clocking Mode register
* • Bit 3, or bit 2 of the Miscellaneous Output register
*
* Also, for quick reference, IBM VGA register values for the standard VGA modes (from http://www.pcjs.org/blog/2015/06/01/):
*
* INT 0x10 Mode Requested: 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x0D 0x0E 0x10 0x12 0x13
*
* BIOSMODE: 0x01 0x01 0x03 0x03 0x04 0x04 0x06 0x0D 0x0E 0x10 0x12 0x13
* CRTC[0x00]: HTOTAL 0x2D 0x2D 0x5F 0x5F 0x2D 0x2D 0x5F 0x2D 0x5F 0x5F 0x5F 0x5F
* CRTC[0x01]: HDISP_END 0x27 0x27 0x4F 0x4F 0x27 0x27 0x4F 0x27 0x4F 0x4F 0x4F 0x4F
* CRTC[0x02]: HBLANK_START 0x28 0x28 0x50 0x50 0x28 0x28 0x50 0x28 0x50 0x50 0x50 0x50
* CRTC[0x03]: HBLANK_END 0x90 0x90 0x82 0x82 0x90 0x90 0x82 0x90 0x82 0x82 0x82 0x82
* CRTC[0x04]: HRETRACE_START 0x2B 0x2B 0x55 0x55 0x2B 0x2B 0x54 0x2B 0x54 0x54 0x54 0x54
* CRTC[0x05]: HRETRACE_END 0xA0 0xA0 0x81 0x81 0x80 0x80 0x80 0x80 0x80 0x80 0x80 0x80
* CRTC[0x06]: VTOTAL 0xBF 0xBF 0xBF 0xBF 0xBF 0xBF 0xBF 0xBF 0xBF 0xBF 0x0B 0xBF
* CRTC[0x07]: OVERFLOW 0x1F 0x1F 0x1F 0x1F 0x1F 0x1F 0x1F 0x1F 0x1F 0x1F 0x3E 0x1F
* CRTC[0x08]: PRESET_ROW 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* CRTC[0x09]: MAX_SCAN 0x4F 0x4F 0x4F 0x4F 0xC1 0xC1 0xC1 0xC0 0xC0 0x40 0x40 0x41
* CRTC[0x0A]: CURSOR_START 0x0D 0x0D 0x0D 0x0D 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* CRTC[0x0B]: CURSOR_END 0x0E 0x0E 0x0E 0x0E 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* CRTC[0x0C]: START_ADDR_HI 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* CRTC[0x0D]: START_ADDR_LO 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* CRTC[0x0E]: CURSOR_ADDR_HI 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x00
* CRTC[0x0F]: CURSOR_ADDR_LO 0x19 0x19 0x41 0x41 0x19 0x19 0x41 0x19 0x41 0x41 0xE1 0xA2
* CRTC[0x10]: VRETRACE_START 0x9C 0x9C 0x9C 0x9C 0x9C 0x9C 0x9C 0x9C 0x9C 0x83 0xEA 0x9C
* CRTC[0x11]: VRETRACE_END 0x8E 0x8E 0x8E 0x8E 0x8E 0x8E 0x8E 0x8E 0x8E 0x85 0x8C 0x8E
* CRTC[0x12]: VDISP_END 0x8F 0x8F 0x8F 0x8F 0x8F 0x8F 0x8F 0x8F 0x8F 0x5D 0xDF 0x8F
* CRTC[0x13]: OFFSET 0x14 0x14 0x28 0x28 0x14 0x14 0x28 0x14 0x28 0x28 0x28 0x28
* CRTC[0x14]: UNDERLINE 0x1F 0x1F 0x1F 0x1F 0x00 0x00 0x00 0x00 0x00 0x0F 0x00 0x40
* CRTC[0x15]: VBLANK_START 0x96 0x96 0x96 0x96 0x96 0x96 0x96 0x96 0x96 0x63 0xE7 0x96
* CRTC[0x16]: VBLANK_END 0xB9 0xB9 0xB9 0xB9 0xB9 0xB9 0xB9 0xB9 0xB9 0xBA 0x04 0xB9
* CRTC[0x17]: MODE_CTRL 0xA3 0xA3 0xA3 0xA3 0xA2 0xA2 0xC2 0xE3 0xE3 0xE3 0xE3 0xA3
* CRTC[0x18]: LINE_COMPARE 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF
* GRC[0x00]: SRESET 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* GRC[0x01]: ESRESET 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* GRC[0x02]: COLORCMP 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* GRC[0x03]: DATAROT 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* GRC[0x04]: READMAP 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* GRC[0x05]: MODE 0x10 0x10 0x10 0x10 0x30 0x30 0x00 0x00 0x00 0x00 0x00 0x40
* GRC[0x06]: MISC 0x0E 0x0E 0x0E 0x0E 0x0F 0x0F 0x0D 0x05 0x05 0x05 0x05 0x05
* GRC[0x07]: COLORDC 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x0F 0x0F 0x0F 0x0F 0x0F
* GRC[0x08]: BITMASK 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF
* SEQ[0x00]: RESET 0x03 0x03 0x03 0x03 0x03 0x03 0x03 0x03 0x03 0x03 0x03 0x03
* SEQ[0x01]: CLOCKING 0x08 0x08 0x00 0x00 0x09 0x09 0x01 0x09 0x01 0x01 0x01 0x01
* SEQ[0x02]: MAPMASK 0x03 0x03 0x03 0x03 0x03 0x03 0x01 0x0F 0x0F 0x0F 0x0F 0x0F
* SEQ[0x03]: CHARMAP 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* SEQ[0x04]: MEMMODE 0x03 0x03 0x03 0x03 0x02 0x02 0x06 0x06 0x06 0x06 0x06 0x0E
* ATC[0x00]: PAL00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* ATC[0x01]: PAL01 0x01 0x01 0x01 0x01 0x13 0x13 0x17 0x01 0x01 0x01 0x01 0x01
* ATC[0x02]: PAL02 0x02 0x02 0x02 0x02 0x15 0x15 0x17 0x02 0x02 0x02 0x02 0x02
* ATC[0x03]: PAL03 0x03 0x03 0x03 0x03 0x17 0x17 0x17 0x03 0x03 0x03 0x03 0x03
* ATC[0x04]: PAL04 0x04 0x04 0x04 0x04 0x02 0x02 0x17 0x04 0x04 0x04 0x04 0x04
* ATC[0x05]: PAL05 0x05 0x05 0x05 0x05 0x04 0x04 0x17 0x05 0x05 0x05 0x05 0x05
* ATC[0x06]: PAL06 0x14 0x14 0x14 0x14 0x06 0x06 0x17 0x06 0x06 0x14 0x14 0x06
* ATC[0x07]: PAL07 0x07 0x07 0x07 0x07 0x07 0x07 0x17 0x07 0x07 0x07 0x07 0x07
* ATC[0x08]: PAL08 0x38 0x38 0x38 0x38 0x10 0x10 0x17 0x10 0x10 0x38 0x38 0x08
* ATC[0x09]: PAL09 0x39 0x39 0x39 0x39 0x11 0x11 0x17 0x11 0x11 0x39 0x39 0x09
* ATC[0x0A]: PAL0A 0x3A 0x3A 0x3A 0x3A 0x12 0x12 0x17 0x12 0x12 0x3A 0x3A 0x0A
* ATC[0x0B]: PAL0B 0x3B 0x3B 0x3B 0x3B 0x13 0x13 0x17 0x13 0x13 0x3B 0x3B 0x0B
* ATC[0x0C]: PAL0C 0x3C 0x3C 0x3C 0x3C 0x14 0x14 0x17 0x14 0x14 0x3C 0x3C 0x0C
* ATC[0x0D]: PAL0D 0x3D 0x3D 0x3D 0x3D 0x15 0x15 0x17 0x15 0x15 0x3D 0x3D 0x0D
* ATC[0x0E]: PAL0E 0x3E 0x3E 0x3E 0x3E 0x16 0x16 0x17 0x16 0x16 0x3E 0x3E 0x0E
* ATC[0x0F]: PAL0F 0x3F 0x3F 0x3F 0x3F 0x17 0x17 0x17 0x17 0x17 0x3F 0x3F 0x0F
* ATC[0x10]: MODE 0x0C 0x0C 0x0C 0x0C 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x41
* ATC[0x11]: OVERSCAN 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
* ATC[0x12]: PLANES 0x0F 0x0F 0x0F 0x0F 0x03 0x03 0x01 0x0F 0x0F 0x0F 0x0F 0x0F
* ATC[0x13]: HPAN 0x08 0x08 0x08 0x08 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
*
* TODO: Build a similar table for the IBM EGA, and then work on rationalizing the mode detection logic in checkMode().
*/
/*
* Supported Modes
*
* Although this component is designed to be a video hardware emulation, not a BIOS simulation, we DO
* look for changes to the hardware state that correspond to standard BIOS mode settings, so our internal
* mode setting will normally match the current BIOS mode setting; however, this a debugging convenience,
* not an attempt to monitor or emulate the BIOS.
*
* We do have some BIOS awareness (eg, when loading ROM-based fonts, and some special code to ensure all
* the BIOS diagnostics pass), but for the most part, we treat the BIOS like any other application code.
*
* As we expand support to include more programmable cards like the EGA, it becomes quite easy for the card
* to enter a "mode" that has no BIOS counterpart (eg, non-standard combinations of video buffer address,
* memory access modes, fonts, display regions, etc). Our hardware emulation routines will cope with those
* situations as best they can (and when they don't, it should be considered a bug if some application is
* broken as a result), but realistically, our hardware emulation is never likely to be 100% accurate.
*/
Video.MODE = {
CGA_40X25_BW: 0,
CGA_40X25: 1,
CGA_80X25_BW: 2,
CGA_80X25: 3,
CGA_320X200: 4,
CGA_320X200_BW: 5,
CGA_640X200: 6,
MDA_80X25: 7,
EGA_320X200: 0x0D, // mapped at A000:0000, color, 4bpp, planar
EGA_640X200: 0x0E, // mapped at A000:0000, color, 4bpp, planar
EGA_640X350_MONO: 0x0F, // mapped at A000:0000, mono, 2bpp, planar
EGA_640X350: 0x10, // mapped at A000:0000, color, 4bpp, planar
VGA_640X480_MONO: 0x11, // mapped at A000:0000, mono, 2bpp, planar
VGA_640X480: 0x12, // mapped at A000:0000, color, 4bpp, planar
VGA_320X200: 0x13, // mapped at A000:0000, color, 8bpp, linear
/*
* The remaining mode identifiers are for internal use only; there is no correlation with any
* publicly defined BIOS modes, and overlap with any third-party mode numbers is purely coincidental.
*/
VGA_320X240: 0x14, // mapped at A000:0000, color, 8bpp, planar ("Mode X")
VGA_320X400: 0x15, // mapped at A000:0000, color, 8bpp, planar
/*
* Here's where we might assign additional identifiers to certain unique combinations, like the
* fTextGraphicsHybrid 320x400 mode that Windows 95 uses (ie, when the buffer is mapped to B800:0000
* instead of A000:0000 and is configured for text mode access, but graphics are still being displayed
* from the second half of video memory).
*/
UNKNOWN: 0xFF
};
/*
* Supported Fonts
*
* Once we've finished loading the standard 8K font file, aFonts[] should contain one or more of the
* entries listed below. For the standard MDA/CGA font ROM, the first (MDA) font resides in the first 4Kb,
* and the second and third (CGA) fonts reside in the two 2K halves of the second 4Kb.
*
* It may seem odd that the cell size for FONT_CGAD is *larger* than the cell size for FONT_CGA,
* since 40-column mode is actually lower resolution, but since we don't shrink the screen canvas when we
* shrink the mode, the characters must be drawn larger, and they look better if we don't have to scale them.
*
* From the IBM EGA Manual (p.5):
*
* "In alphanumeric modes, characters are formed from one of two ROM (Read Only Memory) character
* generators on the adapter. One character generator defines 7x9 characters in a 9x14 character box.
* For Enhanced Color Display support, the 9x14 character set is modified to provide an 8x14 character set.
* The second character generator defines 7x7 characters in an 8x8 character box. These generators contain
* dot patterns for 256 different characters. The character sets are identical to those provided by the
* IBM Monochrome Display Adapter and the IBM Color/Graphics Monitor Adapter."
*/
Video.FONT = {
MDA: 1, // 9x14 monochrome font
MDAD: 2, // 18x28 monochrome font (this is the 9x14 font doubled)
CGA: 3, // 8x8 color font
CGAD: 6, // 16x16 color font (this is the 8x8 CGA font doubled)
EGA: 5, // 8x14 color font
EGAD: 10, // 16x28 color font (this is the 8x14 EGA font doubled)
VGA: 7, // 8x16 color font
VGAD: 14 // 16x32 color font (this is the 8x16 VGA font doubled)
};
/*
* Supported Cards
*
* Note that we choose card IDs that match the default font ID for each card as well, for convenience.
*/
Video.CARD = {
MDA: Video.FONT.MDA,
CGA: Video.FONT.CGA,
EGA: Video.FONT.EGA,
VGA: Video.FONT.VGA
};
/*
* Supported Models
*
* Each model refers to an array where [0] is the card ID, and [1] is the default mode.
*/
Video.MODEL = {
"mda": [Video.CARD.MDA, Video.MODE.MDA_80X25],
"cga": [Video.CARD.CGA, Video.MODE.CGA_80X25],
"ega": [Video.CARD.EGA, Video.MODE.CGA_80X25],
"vga": [Video.CARD.VGA, Video.MODE.CGA_80X25]
};
/*
* Supported Monitors
*
* The MDA monitor displays 350 lines of vertical resolution, 720 lines of horizontal resolution, and refreshes
* at ~50Hz. The CGA monitor displays 200 lines vertically, 640 horizontally, and refreshes at ~60Hz.
*
* Based on actual MDA timings (see http://diylab.atwebpages.com/pressureDev.htm), the total horizontal
* period (drawing a line and retracing) is ~54.25uSec (1000000uSec / 18432) and the horizontal retrace interval
* is about 15% of that, or ~8.14uSec. Vertical sync occurs once every 370 horizontal periods. Of those 370,
* only 354 represent actively drawn lines (and of those, only 350 are visible); the remaining 16 horizontal
* periods, or 4% of the 370 total, represent the vertical retrace interval.
*
* I don't have similar numbers for the CGA or EGA, so for now, I assume similar percentages; ie, 15% of
* the horizontal period will represent horizontal retrace, and 4% of the vertical pixel maximum (262) will
* represent vertical retrace. However, 24% of the CGA's 262 vertical maximum represents non-visible lines,
* whereas only 5% of the MDA's 370 maximum represents non-visible lines; is there really that much "overscan"
* on the CGA?
*
* For each monitor type, there's a Video.monitorSpecs object that describes the horizontal and vertical
* timings, along with my assumptions about the percentage of time that drawing is "active" within those periods,
* and then based on the selected monitor type, I compute the number of CPU cycles that each period lasts,
* as well as the number of CPU cycles that drawing lasts within each period, so that the horizontal and vertical
* retrace status flags can be quickly calculated.
*
* For reference, here are some important numbers to know (from https://github.com/reenigne/reenigne/blob/master/8088/cga/register_values.txt):
*
* CGA MDA
* Pixel clock 14.318 MHz 16.257 MHz (aka "maximum video bandwidth", as IBM Tech Refs sometimes call it)
* Horizontal 15.700 KHz 18.432 KHz (aka "horizontal drive", as IBM Tech Refs sometimes call it)
* Vertical 59.923 Hz 49.816 Hz
* Usage 53.69% 77.22%
* H pix 912 = 114*8 882 = 98*9
* V pix 262 370
* Dots 238944 326340
*/
/**
* @class MonitorSpecs
* @property {number} nHorzPeriodsPerSec
* @property {number} nHorzPeriodsPerFrame
* @property {number} percentHorzActive
* @property {number} percentVertActive
*
* From these monitor specs, we calculate the following values for a given Card:
*
* nCyclesPerSecond = cpu.getCyclesPerSecond(); // eg, 4772727
* nCyclesHorzPeriod = (nCyclesPerSecond / monitorSpecs.nHorzPeriodsPerSec) | 0;
* nCyclesHorzActive = (nCyclesHorzPeriod * monitorSpecs.percentHorzActive / 100) | 0;
* nCyclesVertPeriod = nCyclesHorzPeriod * monitorSpecs.nHorzPeriodsPerFrame;
* nCyclesVertActive = (nCyclesVertPeriod * monitorSpecs.percentVertActive / 100) | 0;
*/
/**
* @type {Object}
*/
Video.monitorSpecs = {};
/**
* NOTE: Based on trial-and-error, 208 is the magic number of horizontal syncs per vertical sync that
* yielded the necessary number of "horizontal enables" (200 or 0xC8) in the EGA ROM BIOS at C000:03D0.
*
* @type {{MonitorSpecs}}
*/
Video.monitorSpecs[ChipSet.MONITOR.COLOR] = {
nHorzPeriodsPerSec: 15700,
nHorzPeriodsPerFrame: 208,
percentHorzActive: 85,
percentVertActive: 96
};
/**
* NOTE: Based on trial-and-error, 364 is the magic number of horizontal syncs per vertical sync that
* yielded the necessary number of "horizontal enables" (350 or 0x15E) in the EGA ROM BIOS at C000:03D0.
*
* @type {{MonitorSpecs}}
*/
Video.monitorSpecs[ChipSet.MONITOR.MONO] = {
nHorzPeriodsPerSec: 18432,
nHorzPeriodsPerFrame: 364,
percentHorzActive: 85,
percentVertActive: 96
};
/**
* @type {{MonitorSpecs}}
*/
Video.monitorSpecs[ChipSet.MONITOR.EGACOLOR] = {
nHorzPeriodsPerSec: 21850,
nHorzPeriodsPerFrame: 364,
percentHorzActive: 85,
percentVertActive: 96
};
/**
* NOTE: As above, the following values are based purely on trial-and-error, to yield results that fall
* squarely within the bounds of the IBM VGA ROM timing requirements; see the IBM VGA ROM code at C000:024A.
*
* @type {{MonitorSpecs}}
*/
Video.monitorSpecs[ChipSet.MONITOR.VGACOLOR] = {
nHorzPeriodsPerSec: 16700,
nHorzPeriodsPerFrame: 480,
percentHorzActive: 85,
percentVertActive: 83
};
/*
* EGA Miscellaneous ports and SW1-Sw4
*
* The Card.MISC.CLOCK_SELECT bits determine which of the EGA board's 4 configuration switches are
* returned via Card.STATUS0.SWSENSE (when SWSENSE is zero, the switch is closed):
*
* 0xC: return SW1
* 0x8: return SW2
* 0x4: return SW3
* 0x0: return SW4
*
* These 4 bits are also copied to the byte at 40:88h by the EGA BIOS, where bit 0 is SW1, bit 1 is SW2,
* bit 2 is SW3 and bit 3 is SW4. Our switch settings come from bEGASwitches, which in turn comes from
* sSwitches, which in turn comes from the "switches" property passed to the Video component, if any.
*
* As usual, the switch settings are reversed in both direction and sense from the switch settings; the
* good news, however, is that we can use the parseSwitches() method in the ChipSet component to parse them.
*
* The set of valid EGA switch values, after conversion, is stored in the table below. For each value,
* there is an array that defines the corresponding monitor type(s) for the EGA adapter and any secondary
* adapter. The third value is a boolean indicating whether the EGA is the primary adapter.
*/
Video.aEGAMonitorSwitches = {
0x06: [ChipSet.MONITOR.TV, ChipSet.MONITOR.MONO, true], // "1001"
0x07: [ChipSet.MONITOR.COLOR, ChipSet.MONITOR.MONO, true], // "0001"
0x08: [ChipSet.MONITOR.EGAEMULATION, ChipSet.MONITOR.MONO, true], // "1110"
0x09: [ChipSet.MONITOR.EGACOLOR, ChipSet.MONITOR.MONO, true], // "0110" [our default; see bEGASwitches below]
0x0a: [ChipSet.MONITOR.MONO, ChipSet.MONITOR.TV, true], // "1010"
0x0b: [ChipSet.MONITOR.MONO, ChipSet.MONITOR.COLOR, true], // "0010"
0x00: [ChipSet.MONITOR.TV, ChipSet.MONITOR.MONO, false], // "1111"
0x01: [ChipSet.MONITOR.COLOR, ChipSet.MONITOR.MONO, false], // "0111"
0x02: [ChipSet.MONITOR.EGAEMULATION, ChipSet.MONITOR.MONO, false], // "1011"
0x03: [ChipSet.MONITOR.EGACOLOR, ChipSet.MONITOR.MONO, false], // "0011"
0x04: [ChipSet.MONITOR.MONO, ChipSet.MONITOR.TV, false], // "1101"
0x05: [ChipSet.MONITOR.MONO, ChipSet.MONITOR.COLOR, false] // "0101"
};
/**
* @class Font
* @property {number} cxCell
* @property {number} cyCell
* @property {Array} aCSSColors
* @property {Array} aRGBColors
* @property {Array} aColorMap
* @property {Array} aCanvas
*/
/*
* For each video mode, we need to know the following pieces of information:
*
* 0: # of columns (nCols)
* 1: # of rows (nRows)
* 2: # cells per word (nCellsPerWord: # of characters or pixels per word)
* 3: # bytes of visible screen padding, if any (used for CGA graphics modes only)
* 4: font ID (nFont: undefined if graphics mode)
*
* For MDA and CGA modes, a "word" of memory is 16 bits of CPU-addressable data, so by calculating
* ([0] * [1]) / [2], we obtain the number of words that mode actively displays; for example, the
* amount of visible memory used by mode 0x04 is (320 * 200) / 4, or 16000.
*
* However, for EGA and VGA graphics modes, a "word" of memory is a single element in the video buffer
* containing 32 bits of pixel data.
*
* The MODES.CGA_40X25 modes specify FONT_CGA instead of FONT_CGAD because we don't automatically
* load the FONT_CGAD unless the screen is large enough to accommodate it (see the fDoubleFont calculation).
*
* To compensate, we have code in setDimensions() that automatically switches to FONT_CGAD if it's loaded AND
* the cell size warrants the larger font. We could hard-code FONT_CGAD here, but then we'd always load it,
* and it might not always be the best fit.
*/
Video.aModeParms = []; // Mode
Video.aModeParms[Video.MODE.CGA_40X25] = [ 40, 25, 1, 0, Video.FONT.CGA]; // 0x01
Video.aModeParms[Video.MODE.CGA_80X25] = [ 80, 25, 1, 0, Video.FONT.CGA]; // 0x03
Video.aModeParms[Video.MODE.CGA_320X200] = [320, 200, 8, 192]; // 0x04
Video.aModeParms[Video.MODE.CGA_640X200] = [640, 200, 16, 192]; // 0x06
Video.aModeParms[Video.MODE.MDA_80X25] = [ 80, 25, 1, 0, Video.FONT.MDA]; // 0x07
Video.aModeParms[Video.MODE.EGA_320X200] = [320, 200, 8]; // 0x0D
Video.aModeParms[Video.MODE.EGA_640X200] = [640, 200, 8]; // 0x0E
Video.aModeParms[Video.MODE.EGA_640X350_MONO] = [640, 350, 8]; // 0x0F
Video.aModeParms[Video.MODE.EGA_640X350] = [640, 350, 8]; // 0x10
Video.aModeParms[Video.MODE.VGA_640X480_MONO] = [640, 480, 8]; // 0x11
Video.aModeParms[Video.MODE.VGA_640X480] = [640, 480, 8]; // 0x12
Video.aModeParms[Video.MODE.VGA_320X200] = [320, 200, 1]; // 0x13
Video.aModeParms[Video.MODE.VGA_320X240] = [320, 240, 4]; // 0x14
Video.aModeParms[Video.MODE.VGA_320X400] = [320, 400, 4]; // 0x15
Video.aModeParms[Video.MODE.CGA_40X25_BW] = Video.aModeParms[Video.MODE.CGA_40X25]; // 0x00
Video.aModeParms[Video.MODE.CGA_80X25_BW] = Video.aModeParms[Video.MODE.CGA_80X25]; // 0x02
Video.aModeParms[Video.MODE.CGA_320X200_BW] = Video.aModeParms[Video.MODE.CGA_320X200]; // 0x05
/*
* MDA attribute byte definitions
*
* For MDA, only the following group of ATTR definitions are supported; any FGND/BGND value combinations
* outside this group will be treated as "normal" (ATTR_FGND_WHITE | ATTR_BGND_BLACK).
*
* NOTE: Assuming MDA.MODE.BLINK_ENABLE is set (which the ROM BIOS sets by default), ATTR_BGND_BLINK will
* cause the *foreground* element of the cell to blink, even though it is part of the *background* attribute bits.
*
* Regarding blink rate, characters are supposed to blink every 16 vertical frames, which amounts to .26667 blinks
* per second, assuming a 60Hz vertical refresh rate. So roughly every 267ms, we need to take care of any blinking
* characters. updateScreen() maintains a global count (cBlinkVisible) of blinking characters, to simplify the
* decision of when to redraw the screen.
*/
Video.ATTRS = {};
Video.ATTRS.FGND_BLACK = 0x00;
Video.ATTRS.FGND_ULINE = 0x01;
Video.ATTRS.FGND_WHITE = 0x07;
Video.ATTRS.FGND_BRIGHT = 0x08;
Video.ATTRS.BGND_BLACK = 0x00;
Video.ATTRS.BGND_WHITE = 0x70;
Video.ATTRS.BGND_BLINK = 0x80;
Video.ATTRS.BGND_BRIGHT = 0x80;
Video.ATTRS.DRAW_FGND = 0x100; // this is an internal attribute bit, indicating the foreground should be drawn
Video.ATTRS.DRAW_CURSOR = 0x200; // this is an internal attribute bit, indicating when the cursor should be drawn
/*
* Here's a "cheat sheet" for attribute byte combinations that the IBM MDA could have supported. The original (Aug 1981)
* IBM Tech Ref is very terse and implies that only those marked with * are actually supported.
*
* *0x00: non-display ATTR_FGND_BLACK | ATTR_BGND_BLACK
* *0x01: underline ATTR_FGND_ULINE | ATTR_BGND_BLACK
* *0x07: normal (white on black) ATTR_FGND_WHITE | ATTR_BGND_BLACK
* **0x09: bright underline ATTR_FGND_ULINE | ATTR_FGND_BRIGHT | ATTR_BGND_BLACK
* **0x0F: bold (bright white on black) ATTR_FGND_WHITE | ATTR_FGND_BRIGHT | ATTR_BGND_BLACK
* *0x70: reverse (black on white) ATTR_FGND_BLACK | | ATTR_BGND_WHITE
* 0x81: blinking underline ATTR_FGND_ULINE | | ATTR_BGND_BLINK (or dim background if blink disabled)
* **0x87: blinking normal ATTR_FGND_WHITE | | ATTR_BGND_BLINK (or dim background if blink disabled)
* 0x89: blinking bright underline ATTR_FGND_ULINE | ATTR_FGND_BRIGHT | ATTR_BGND_BLINK (or dim background if blink disabled)
* **0x8F: blinking bold ATTR_FGND_WHITE | ATTR_FGND_BRIGHT | ATTR_BGND_BLINK (or dim background if blink disabled)
* **0xF0: blinking reverse ATTR_FGND_WHITE | ATTR_FGND_BRIGHT | ATTR_BGND_BLINK (or bright background if blink disabled)
*
* Unsupported attributes reportedly display as "normal" (ATTR_FGND_WHITE | ATTR_BGND_BLACK). However, precisely which
* attributes are unsupported on the MDA varies depending on the source. Some sources (eg, the IBM Tech Ref) imply that
* only those marked by * are supported, while others (eg, some--but not all--Peter Norton guides) include those marked
* by **, and still others include ALL the combinations listed above.
*
* Furthermore, according to http://www.seasip.info/VintagePC/mda.html:
*
* Attributes 0x00, 0x08, 0x80 and 0x88 display as black space;
* Attribute 0x78 displays as dark green on green; depending on the monitor, there may be a green "halo" where the dark and bright bits meet;
* Attribute 0xF0 displays as a blinking version of 0x70 if blink enabled, and black on bright green otherwise;
* Attribute 0xF8 displays as a blinking version of 0x78 if blink enabled, and as dark green on bright green otherwise.
*
* However, I'm rather skeptical about supporting 0x78 and 0xF8, until I see some evidence that "bright black" actually
* produced dark green on IBM equipment; it also doesn't sound like a combination many people would have used. I'll probably
* treat all of 0x08, 0x80 and 0x88 the same as 0x00, only because it seems logical (they're all "black on black" combinations
* with only BRIGHT and/or BLINK bits set). Beyond that, I'll likely treat any other combination not listed in the above cheat
* sheet as "normal".
*
* All the discrepancies/disagreements I've found are probably due in part to the proliferation of IBM and non-IBM MDA
* cards, combined with IBM and non-IBM monochrome monitors, and people assuming that their non-IBM card and/or monitor
* behaved exactly like the original IBM equipment, which probably wasn't true in all cases.
*
* I would like to limit my MDA display support to EXACTLY everything that the IBM MDA supported and nothing more, but
* since there will be combinations that will logically "fall out" unless I specifically exclude them, it's very likely
* this implementation will end up being a superset.
*/
/*
* CGA attribute byte definitions; these simply extend the set of MDA attributes, with the exception of ATTR_FNGD_ULINE,
* which the CGA can treat only as ATTR_FGND_BLUE.
*/
Video.ATTRS.FGND_BLUE = 0x01;
Video.ATTRS.FGND_GREEN = 0x02;
Video.ATTRS.FGND_CYAN = 0x03;
Video.ATTRS.FGND_RED = 0x04;
Video.ATTRS.FGND_MAGENTA = 0x05;
Video.ATTRS.FGND_BROWN = 0x06;
Video.ATTRS.BGND_BLUE = 0x10;
Video.ATTRS.BGND_GREEN = 0x20;
Video.ATTRS.BGND_CYAN = 0x30;
Video.ATTRS.BGND_RED = 0x40;
Video.ATTRS.BGND_MAGENTA = 0x50;
Video.ATTRS.BGND_BROWN = 0x60;
/*
* For the MDA, the number of unique "colors" is 5, based on the following supported FGND attribute values:
*
* 0x0: black font (attribute value 0x8 is mapped to 0x0)
* 0x1: green font with underline
* 0x7: green font without underline (attribute values 0x2-0x6 are mapped to 0x7)
* 0x9: bright green font with underline
* 0xf: bright green font without underline (attribute values 0xa-0xe are mapped to 0xf)
*
* I'm still not sure about 0x8 (dark green?); for now, I'm mapping it to 0x0, but it may become a 6th supported color.
*
* MDA attributes form an index into aMDAColorMap, which in turn provides an index (0-4) into aMDAColors.
*/
Video.aMDAColors = [
[0x00, 0x00, 0x00, 0xff],
[0x7f, 0xc0, 0x7f, 0xff],
[0x7f, 0xc0, 0x7f, 0xff],
[0x7f, 0xff, 0x7f, 0xff],
[0x7f, 0xff, 0x7f, 0xff]
];
Video.aMDAColorMap = [0x0, 0x1, 0x2, 0x2, 0x2, 0x2, 0x2, 0x2, 0x0, 0x3, 0x4, 0x4, 0x4, 0x4, 0x4, 0x4];
Video.aCGAColors = [
[0x00, 0x00, 0x00, 0xff], // 0x00: ATTR_FGND_BLACK
[0x00, 0x00, 0xaa, 0xff], // 0x01: ATTR_FGND_BLUE
[0x00, 0xaa, 0x00, 0xff], // 0x02: ATTR_FGND_GREEN
[0x00, 0xaa, 0xaa, 0xff], // 0x03: ATTR_FGND_CYAN
[0xaa, 0x00, 0x00, 0xff], // 0x04: ATTR_FGND_RED
[0xaa, 0x00, 0xaa, 0xff], // 0x05: ATTR_FGND_MAGENTA
[0xaa, 0x55, 0x00, 0xff], // 0x06: ATTR_FGND_BROWN
[0xaa, 0xaa, 0xaa, 0xff], // 0x07: ATTR_FGND_WHITE (aka light gray)
[0x55, 0x55, 0x55, 0xff], // 0x08: ATTR_FGND_BLACK | ATTR_FGND_BRIGHT (aka gray)
[0x55, 0x55, 0xff, 0xff], // 0x09: ATTR_FGND_BLUE | ATTR_FGND_BRIGHT
[0x55, 0xff, 0x55, 0xff], // 0x0A: ATTR_FGND_GREEN | ATTR_FGND_BRIGHT
[0x55, 0xff, 0xff, 0xff], // 0x0B: ATTR_FGND_CYAN | ATTR_FGND_BRIGHT
[0xff, 0x55, 0x55, 0xff], // 0x0C: ATTR_FGND_RED | ATTR_FGND_BRIGHT
[0xff, 0x55, 0xff, 0xff], // 0x0D: ATTR_FGND_MAGENTA | ATTR_FGND_BRIGHT
[0xff, 0xff, 0x55, 0xff], // 0x0E: ATTR_FGND_BROWN | ATTR_FGND_BRIGHT (aka yellow)
[0xff, 0xff, 0xff, 0xff] // 0x0F: ATTR_FGND_WHITE | ATTR_FGND_BRIGHT (aka white)
];
Video.aCGAColorSet1 = [Video.ATTRS.FGND_GREEN, Video.ATTRS.FGND_RED, Video.ATTRS.FGND_BROWN];
Video.aCGAColorSet2 = [Video.ATTRS.FGND_CYAN, Video.ATTRS.FGND_MAGENTA, Video.ATTRS.FGND_WHITE];
/*
* Here is the EGA BIOS default ATC palette register set for color text modes, from which getCardColors()
* builds a default RGB array, similar to aCGAColors above.
*/
Video.aEGAPalDef = [0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x14, 0x07, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F];
Video.aEGAByteToDW = [
0x00000000, 0x000000ff, 0x0000ff00, 0x0000ffff,
0x00ff0000, 0x00ff00ff, 0x00ffff00, 0x00ffffff,
0xff000000|0, 0xff0000ff|0, 0xff00ff00|0, 0xff00ffff|0,
0xffff0000|0, 0xffff00ff|0, 0xffffff00|0, 0xffffffff|0
];
Video.aEGADWToByte = [];
Video.aEGADWToByte[0x00000000] = 0x0;
Video.aEGADWToByte[0x00000080] = 0x1;
Video.aEGADWToByte[0x00008000] = 0x2;
Video.aEGADWToByte[0x00008080] = 0x3;
Video.aEGADWToByte[0x00800000] = 0x4;
Video.aEGADWToByte[0x00800080] = 0x5;
Video.aEGADWToByte[0x00808000] = 0x6;
Video.aEGADWToByte[0x00808080] = 0x7;
Video.aEGADWToByte[0x80000000|0] = 0x8;
Video.aEGADWToByte[0x80000080|0] = 0x9;
Video.aEGADWToByte[0x80008000|0] = 0xa;
Video.aEGADWToByte[0x80008080|0] = 0xb;
Video.aEGADWToByte[0x80800000|0] = 0xc;
Video.aEGADWToByte[0x80800080|0] = 0xd;
Video.aEGADWToByte[0x80808000|0] = 0xe;
Video.aEGADWToByte[0x80808080|0] = 0xf;
/**
* Card(video, nCard, data, cbMemory)
*
* Creates an object representing an initial video card state;
* can also restore a video card from state data created by saveCard().
*
* WARNING: Since Card objects are low-level objects that have no UI requirements,
* they do not inherit from the Component class, so you should only use class methods
* of Component, such as Component.assert(), or methods of the parent (video) object.
*
* @constructor
* @param {Video} [video]
* @param {number} [nCard] (see Video.CARD.*)
* @param {Array|null} [data]
* @param {number} [cbMemory] is specified if the card must allocate its own memory buffer
*/
function Card(video, nCard, data, cbMemory)
{
/*
* If a card was originally not present (eg, EGA), then the state will be empty,
* so we need to detect that case and continue indicating that the card is not present.
*/
if (nCard !== undefined && (!data || data.length)) {
this.video = video;
var specs = Video.cardSpecs[nCard];
var nMonitorType = video.nMonitorType || specs[5];
if (!data || data.length < 6) {
data = [false, 0, null, null, 0, new Array(nCard < Video.CARD.EGA? Card.CRTC.TOTAL_REGS : Card.CRTC.EGA.TOTAL_REGS)];
}
/*
* If a Debugger is present, we want to stash a bit more info in each Card.
*/
if (DEBUGGER) {
this.dbg = video.dbg;
this.type = specs[0];
this.port = specs[1];
}
this.nCard = nCard;
this.addrBuffer = specs[2]; // default (physical) video buffer address
this.sizeBuffer = specs[3]; // default video buffer length (this is the total size, not the current visible size; this.cbScreen is calculated on the fly to reflect the latter)
/*
* If no memory size is specified, then setMode() will use addMemory() to automatically add enough
* memory blocks to cover the video buffer specified above; otherwise, it instructs addMemory() to call
* getMemoryBuffer(), which will return a portion of the buffer (adwMemory) allocated below. This allows
* a card like the EGA to move/resize its video buffer as needed, as well as giving it total control over
* the underlying memory.
*/
this.cbMemory = cbMemory || specs[4];
/*
* All of our cardSpec video buffer sizes are based on the default text mode (eg, 4Kb for an MDA, 16Kb for
* a CGA), but for a card with 64Kb or more of memory (ie, any EGA card), the default text mode video buffer
* size should be dynamically recalculated as the smaller of: cbMemory divided by 4, or 32Kb.
*/
if (this.cbMemory >= 0x10000 && this.addrBuffer >= 0xB0000) {
this.sizeBuffer = Math.min(this.cbMemory >> 2, 0x8000);
}
this.fActive = data[0];
this.regMode = data[1]; // see MDA.MODE* or CGA.MODE_* (use (MDA.MODE.HIRES | MDA.MODE.VIDEO_ENABLE | MDA.MODE.BLINK_ENABLE) if you want to test blinking immediately after the initial power-on reset)
this.regColor = data[2]; // see CGA.COLOR.* (undefined on MDA)
this.regStatus = data[3]; // see MDA.STATUS.* or CGA.STATUS.*
this.regCRTIndx = data[4] & 0xff;
this.regCRTPrev = (data[4] >> 8) & 0xff;
this.regCRTData = data[5];
this.nCRTCRegs = Card.CRTC.TOTAL_REGS;
this.asCRTCRegs = DEBUGGER? Card.CRTC.REGS : [];
if (nCard >= Video.CARD.EGA) {
this.nCRTCRegs = Card.CRTC.EGA.TOTAL_REGS;
this.asCRTCRegs = DEBUGGER? Card.CRTC.EGA_REGS : [];
this.initEGA(data[6], nMonitorType);
}
var monitorSpecs = Video.monitorSpecs[nMonitorType] || Video.monitorSpecs[ChipSet.MONITOR.MONO];
var nCyclesPerSecond = video.cpu.getCyclesPerSecond(); // eg, 4772727
this.nCyclesHorzPeriod = (nCyclesPerSecond / monitorSpecs.nHorzPeriodsPerSec)|0;
this.nCyclesHorzActive = (this.nCyclesHorzPeriod * monitorSpecs.percentHorzActive / 100)|0;
this.nCyclesVertPeriod = (this.nCyclesHorzPeriod * monitorSpecs.nHorzPeriodsPerFrame)|0;
this.nCyclesVertActive = (this.nCyclesVertPeriod * monitorSpecs.percentVertActive / 100)|0;
this.nInitCycles = (data[7] || 0);
}
}
/*
* MDA Registers (ports 0x3B4, 0x3B5, 0x3B8, and 0x3BA)
*/
Card.MDA = {
CRTC: {
INDX: {
PORT: 0x3B4, // NOTE: the low byte of this port address (0xB4) is mirrored at 40:0063 (0x0463)
MASK: 0x1F
},
DATA: {
PORT: 0x3B5
}
},
MODE: {
PORT: 0x3B8, // Mode Select Register, aka CRT Control Port 1 (write-only); the BIOS mirrors this register at 40:0065 (0x0465)
HIRES: 0x01,
VIDEO_ENABLE: 0x08,
BLINK_ENABLE: 0x20
},
STATUS: {
PORT: 0x3BA,
HDRIVE: 0x01,
BWVIDEO: 0x08
},
/*
* TODO: Add support for parallel port(s) someday....
*/
PRT_DATA: {
PORT: 0x3BC
},
PRT_STATUS: {
PORT: 0x3BD
},
PRT_CTRL: {
PORT: 0x3BE
}
};
/*
* CGA Registers (ports 0x3D4, 0x3D5, 0x3D8, 0x3D9, and 0x3DA)
*/
Card.CGA = {
CRTC: {
INDX: {
PORT: 0x3D4, // NOTE: the low byte of this port address (0xB4) is mirrored at 40:0063 (0x0463)
MASK: 0x1F
},
DATA: {
PORT: 0x3D5
}
},
MODE: {
PORT: 0x3D8, // Mode Select Register (write-only); the BIOS mirrors this register at 40:0065 (0x0465)
_80X25: 0x01,
GRAPHIC_SEL: 0x02,
BW_SEL: 0x04,
VIDEO_ENABLE: 0x08, // same as MDA.MODE.VIDEO_ENABLE
HIRES_BW: 0x10,
BLINK_ENABLE: 0x20 // same as MDA.MODE.BLINK_ENABLE
},
COLOR: {
PORT: 0x3D9, // write-only
BORDER: 0x07,
BRIGHT: 0x08,
BGND_ALT: 0x10, // alternate, intensified background colors in text mode
COLORSET2: 0x20 // selects aCGAColorSet2 colors for 320x200 graphics mode; aCGAColorSet1 otherwise
},
STATUS: {
PORT: 0x3DA, // read-only; same for EGA (although the EGA calls this STATUS1, to distinguish it from STATUS0)
RETRACE: 0x01,
PEN_TRIGGER: 0x02,
PEN_ON: 0x04,
VRETRACE: 0x08 // when set, this indicates the CGA is performing a vertical retrace
},
/*
* TODO: Add support for light pen port(s) someday....
*/
CLEAR_PEN: {
PORT: 0x3DB
},
PRESET_PEN: {
PORT: 0x3DC
}
};
/*
* Common CRT hardware registers (ports 0x3B4/0x3B5 or 0x3D4/0x3D5)
*
* NOTE: In this implementation, because we have to make at least two of the registers readable (CURSOR_ADDR_HI and CURSOR_ADDR_LO),
* we end up making ALL the registers readable, otherwise we would have to explicitly block any register marked write-only. I don't
* think making the CRT registers fully readable presents any serious compatibility issues, and it actually offers some benefits
* (eg, improved debugging).
*
* However, some things are broken: the (readable) light pen registers on the EGA are overloaded as (writable) vertical retrace
* registers, so the vertical retrace registers cannot actually be read that way. I'm sure the VGA solved that problem, but I haven't
* looked into it yet.
*/
Card.CRTC = {
HTOTAL: 0x00,
HDISP: 0x01,
HSYNC_POS: 0x02,
HSYNC_WIDTH: 0x03,
VTOTAL: 0x04,
VTOTAL_ADJ: 0x05,
VDISP_TOTAL: 0x06,
VSYNC_POS: 0x07,
INTERLACE_POS: 0x08,
MAX_SCAN: {
INDX: 0x09,
MASK: 0x1F
},
CURSOR_START: {
INDX: 0x0A,
MASK: 0x1F,
/*
* I don't entirely understand these cursor blink control bits. Here's what the MC6845 datasheet says:
*
* Bit 5 is the blink timing control. When bit 5 is low, the blink frequency is 1/16 of the vertical field rate,
* and when bit 5 is high, the blink frequency is 1/32 of the vertical field rate. Bit 6 is used to enable a blink.
*/
BLINKON: 0x00, // (supposedly, 0x04 has the same effect as 0x00)
BLINKOFF: 0x20, // if blinking is disabled, the cursor is effectively hidden
BLINKFAST: 0x60 // default is 1/16 of the frame rate; this switches to 1/32 of the frame rate
},
CURSOR_END: {
INDX: 0x0B,
MASK: 0x1F
},
START_ADDR_HI: 0x0C,
START_ADDR_LO: 0x0D,
CURSOR_ADDR_HI: 0x0E,
CURSOR_ADDR_LO: 0x0F,
LIGHT_PEN_HI: 0x10,
LIGHT_PEN_LO: 0x11,
TOTAL_REGS: 0x12, // total CRT registers on MDA/CGA
EGA: {
HDISP_END: 0x01,
HBLANK_START: 0x02,
HBLANK_END: 0x03,
HRETRACE_START: 0x04,
HRETRACE_END: 0x05,
VTOTAL: 0x06,
OVERFLOW: {
INDX: 0x07,
VTOTAL_BIT8: 0x01, // bit 8 of register 0x06
VDISP_END_BIT8: 0x02, // bit 8 of register 0x12
VRETRACE_START_BIT8:0x04, // bit 8 of register 0x10
VBLANK_START_BIT8: 0x08, // bit 8 of register 0x15
LINE_COMPARE_BIT8: 0x10, // bit 8 of register 0x18
CURSOR_START_BIT8: 0x20, // bit 8 of register 0x0A (EGA only)
VTOTAL_BIT9: 0x20, // bit 9 of register 0x06 (VGA only)
VDISP_END_BIT9: 0x40, // bit 9 of register 0x12 (VGA only, unused on EGA)
VRETRACE_START_BIT9:0x80 // bit 9 of register 0x10 (VGA only, unused on EGA)
},
PRESET_SCAN: 0x08,
/*
* NOTE: EGA/VGA CRTC registers 0x09-0x0F are the same as the MDA/CGA CRTC registers defined above
*/
MAX_SCAN: {
INDX: 0x09,
SCAN_LINE: 0x1f,
VBLANK_START_BIT9: 0x20, // (VGA only)
LINE_COMPARE_BIT9: 0x40, // (VGA only)
CONVERT400: 0x80 // 200-to-400 scan-line conversion is in effect (VGA only)
},
CURSOR_START: {
INDX: 0x0A,
MASK: 0x1F,
BLINKON: 0x00, // (VGA only; supposedly, 0x04 has the same effect as 0x00)
BLINKOFF: 0x20, // if blinking is disabled, the cursor is effectively hidden (VGA only)
BLINKFAST: 0x60 // default is 1/16 of the frame rate; this switches to 1/32 of the frame rate (VGA only)
},
CURSOR_END: {
INDX: 0x0B,
MASK: 0x1F
},
START_ADDR_HI: 0x0C,
START_ADDR_LO: 0x0D,
CURSOR_ADDR_HI: 0x0E,
CURSOR_ADDR_LO: 0x0F,
VRETRACE_START: 0x10,
VRETRACE_END: 0x11,
VDISP_END: 0x12,
/*
* The OFFSET register (bits 0-7) specifies the logical line width of the screen. The starting memory address
* for the next character row is larger than the current character row by two or four times this amount.
* The OFFSET register is programmed with a word address. Depending on the method of clocking the CRT Controller,
* this word address is [effectively] either a word or double-word address. #IBMVGATechRef
*/
OFFSET: 0x13,
UNDERLINE: {
INDX: 0x14,
ROWSCAN: 0x1f,
COUNTBY4: 0x20, // (VGA only)
DWORD: 0x40 // (VGA only)
},
VBLANK_START: 0x15,
VBLANK_END: 0x16,
MODE_CTRL: {
INDX: 0x17,
COMPAT_MODE: 0x01, // Compatibility Mode Support (CGA A13 control)
SEL_ROW_SCAN: 0x02, // Select Row Scan Counter
SEL_HRETRACE: 0x04, // Horizontal Retrace Select
COUNTBY2: 0x08, // Count By Two
OUTPUT_CTRL: 0x10, // Output Control
ADDR_WRAP: 0x20, // Address Wrap (in Word mode, 1 maps A15 to A0 and 0 maps A13; use the latter when only 64Kb is installed)
BYTE_MODE: 0x40, // Byte Mode (1 selects Byte Mode; 0 selects Word Mode)
HARD_RESET: 0x80 // Hardware Reset
},
LINE_COMPARE: 0x18,
TOTAL_REGS: 0x19 // total CRT registers on EGA/VGA
},
ADDR_HI_MASK: 0x3F
};
if (DEBUGGER) {
Card.CRTC.REGS = ["HTOTAL","HDISP","HSYNC_POS","HSYNC_WIDTH","VTOTAL","VTOTAL_ADJ",
"VDISP","VSYNC_POS","INTERLACE_POS","MAX_SCAN","CURSOR_START","CURSOR_END",
"START_ADDR_HI","START_ADDR_LO","CURSOR_ADDR_HI","CURSOR_ADDR_LO","LIGHT_PEN_HI","LIGHT_PEN_LO"];
Card.CRTC.EGA_REGS = ["HTOTAL","HDISP_END","HBLANK_START","HBLANK_END","HRETRACE_START","HRETRACE_END",
"VTOTAL","OVERFLOW","PRESET_SCAN","MAX_SCAN","CURSOR_START","CURSOR_END",
"START_ADDR_HI","START_ADDR_LO","CURSOR_ADDR_HI","CURSOR_ADDR_LO","VRETRACE_START","VRETRACE_END",
"VDISP_END","OFFSET","UNDERLINE","VBLANK_START","VBLANK_END","MODE_CTRL","LINE_COMPARE"];
}
/*
* EGA/VGA Input Status 1 Register (port 0x3DA)
*
* STATUS1 bit 0 has confusing documentation: the EGA Tech Ref says "Logical 0 indicates the CRT raster is in a
* horizontal or vertical retrace interval", whereas the VGA Tech Ref says "Logical 1 indicates a horizontal or
* vertical retrace interval," but then clarifies: "This bit is the real-time status of the INVERTED display enable
* signal". So, instead of calling bit 0 DISP_ENABLE (or more precisely, DISP_ENABLE_INVERTED), it's simply RETRACE.
*
* STATUS1 diagnostic bits 5 and 4 are set according to the Card.ATC.PLANES.MUX bits:
*
* MUX Bit 5 Bit 4
* --- ---- ----
* 00: Red Blue
* 01: SecBlue Green
* 10: SecRed SecGreen
* 11: unused unused
*/
Card.STATUS1 = {
PORT: 0x3DA,
RETRACE: 0x01, // bit 0: logical OR of horizontal and vertical retrace
VRETRACE: 0x08, // bit 3: set during vertical retrace interval
DIAGNOSTIC: 0x30, // bits 5,4 are controlled by the Card.ATC.PLANES.MUX bits
RESERVED: 0xC6
};
/*
* EGA/VGA Attribute Controller Registers (port 0x3C0: regATCIndx and regATCData)
*
* The current ATC INDX value is stored in cardEGA.regATCIndx (including the Card.ATC.INDX_ENABLE bit), and the
* ATC DATA values are stored in cardEGA.regATCData. The state of the ATC INDX/DATA flip-flop is stored in fATCData.
*
* Note that the ATC palette registers (0x0-0xf) all use the following 6 bit assignments, with bits 6 and 7 unused:
*
* 0: Blue
* 1: Green
* 2: Red
* 3: SecBlue (or mono video)
* 4: SecGreen (or intensity)
* 5: SecRed
*/
Card.ATC = {
PORT: 0x3C0, // ATC Index/Data Port
INDX_MASK: 0x1F,
INDX_PAL_ENABLE: 0x20, // must be clear when loading palette registers
PALETTE: {
INDX: 0x00, // 16 registers: 0x00 - 0x0F
MASK: 0x3f,
BLUE: 0x01,
GREEN: 0x02,
RED: 0x04,
SECBLUE: 0x08,
BRIGHT: 0x10, // NOTE: The IBM EGA manual (p.56) also calls this the "intensity" bit
SECGREEN: 0x10,
SECRED: 0x20
},
PALETTE_REGS: 0x10, // 16 total palette registers
MODE: {
INDX: 0x10, // ATC Mode Control Register
GRAPHICS: 0x01, // bit 0: set for graphics mode, clear for alphanumeric mode
MONOEM: 0x02, // bit 1: set for monochrome emulation mode, clear for color emulation
TEXT_9DOT: 0x04, // bit 2: set for 9-dot replication in character codes 0xC0-0xDF
BLINK_ENABLE: 0x08, // bit 3: set for text/graphics blink, clear for background intensity
RESERVED: 0x10, // bit 4: reserved
PANCOMPAT: 0x20, // bit 5: set for pixel-panning compatibility
PELWIDTH: 0x40, // bit 6: set for 256-color modes, clear for all other modes
COLORSEL_ALL: 0x80 // bit 7: set to enable all COLORSEL bits (ie, COLORSEL.DAC_BIT5 and COLORSEL.DAC_BIT4)
},
OVERSCAN: {
INDX: 0x11 // ATC Overscan Color Register
},
PLANES: {
INDX: 0x12, // ATC Color Plane Enable Register
MASK: 0x0F,
MUX: 0x30,
RESERVED: 0xC0
},
HPAN: {
INDX: 0x13, // ATC Horizontal PEL Panning Register
SHIFT_LEFT: 0x0F // bits 0-3 indicate # of pixels to shift left
},
COLORSEL: {
INDX: 0x14, // ATC Color Select Register (VGA only)
DAC_BIT7: 0x08, // specifies bit 7 of DAC values (ignored in 256-color modes)
DAC_BIT6: 0x04, // specifies bit 6 of DAC values (ignored in 256-color modes)
DAC_BIT5: 0x02, // specifies bit 5 of DAC values (if ATC.MODE.COLORSEL_ALL is set; ignored in 256-color modes)
DAC_BIT4: 0x01 // specifies bit 4 of DAC values (if ATC.MODE.COLORSEL_ALL is set; ignored in 256-color modes)
},
TOTAL_REGS: 0x14
};
if (DEBUGGER) {
Card.ATC.REGS = ["PAL00","PAL01","PAL02","PAL03","PAL04","PAL05","PAL06","PAL07",
"PAL08","PAL09","PAL0A","PAL0B","PAL0C","PAL0D","PAL0E","PAL0F", "MODE","OVERSCAN","PLANES","HPAN"];
}
/*
* EGA/VGA Feature Control Register (port 0x3BA or 0x3DA: regFeat)
*
* The EGA BIOS writes 0x1 to Card.FEAT_CTRL.BITS and reads Card.STATUS0.FEAT, then writes 0x2 to
* Card.FEAT_CTRL.BITS and reads Card.STATUS0.FEAT. The bits from the first and second reads are shifted
* into the high nibble of the byte at 40:88h.
*/
Card.FEAT_CTRL = {
PORT_MONO: 0x3BA, // write port address (other than the two bits below, the rest are reserved and/or unused)
PORT_COLOR: 0x3DA, // write port address (other than the two bits below, the rest are reserved and/or unused)
PORT_READ: 0x3CA, // read port address (VGA only)
BITS: 0x03 // feature control bits
};
/*
* EGA/VGA Miscellaneous Output Register (port 0x3C2: regMisc)
*/
Card.MISC = {
PORT_WRITE: 0x3C2, // write port address (EGA and VGA)
PORT_READ: 0x3CC, // read port addresss (VGA only)
IO_SELECT: 0x01, // 0 sets CRT ports to 0x3Bn, 1 sets CRT ports to 0x3Dn
ENABLE_RAM: 0x02, // 0 disables video RAM, 1 enables
CLOCK_SELECT: 0x0C, // 0x0: 14Mhz I/O clock, 0x4: 16Mhz on-board clock, 0x8: external clock, 0xC: unused
DISABLE_DRV: 0x10, // 0 activates internal video drivers, 1 activates feature connector direct drive outputs
PAGE_ODD_EVEN: 0x20, // 0 selects the low 64Kb page of video RAM for text modes, 1 selects the high page
HPOLARITY: 0x40, // 0 selects positive horizontal retrace
VPOLARITY: 0x80 // 0 selects positive vertical retrace
};
/*
* EGA/VGA Input Status 0 Register (port 0x3C2: regStatus0)
*/
Card.STATUS0 = {
PORT: 0x3C2, // read-only (aka STATUS0, to distinguish it from PORT_CGA_STATUS)
RESERVED: 0x0F,
SWSENSE: 0x10,
SWSENSE_SHIFT: 4,
FEAT: 0x60, // VGA: reserved
INTERRUPT: 0x80 // 1: video is being displayed; 0: vertical retrace is occurring
};
/*
* VGA Subsystem Enable Register (port 0x3C3: regVGAEnable)
*/
Card.VGA_ENABLE = {
PORT: 0x3C3,
ENABLED: 0x01, // when set, all VGA I/O and memory decoding is enabled; otherwise disabled (TODO: Implement)
RESERVED: 0xFE
};
/*
* EGA/VGA Sequencer Registers (ports 0x3C4/0x3C5: regSEQIndx and regSEQData)
*/
Card.SEQ = {
INDX: {
PORT: 0x3C4, // Sequencer Index Port
MASK: 0x07
},
DATA: {
PORT: 0x3C5 // Sequencer Data Port
},
RESET: {
INDX: 0x00, // Sequencer Reset Register
ASYNC: 0x01,
SYNC: 0x02
},
CLOCKING: {
INDX: 0x01, // Sequencer Clocking Mode Register
DOTS8: 0x01, // 1: 8 dots; 0: 9 dots
BANDWIDTH: 0x02, // 0: CRTC has access 4 out of every 5 cycles (for high-res modes); 1: CRTC has access 2 out of 5 (VGA: reserved)
SHIFTLOAD: 0x04,
DOTCLOCK: 0x08, // 0: normal dot clock; 1: master clock divided by two (used for 320x200 modes: 0, 1, 4, 5, and D)
SHIFT4: 0x10, // VGA only
SCREEN_OFF: 0x20, // VGA only
RESERVED: 0xC0
},
MAPMASK: {
INDX: 0x02, // Sequencer Map Mask Register
PL0: 0x01,
PL1: 0x02,
PL2: 0x04,
PL3: 0x08,
MAPS: 0x0F,
RESERVED: 0xF0
},
CHARMAP: {
INDX: 0x03, // Sequencer Character Map Select Register
SELB: 0x03, // 0x0: 1st 8Kb of plane 2; 0x1: 2nd 8Kb; 0x2: 3rd 8Kb; 0x3: 4th 8Kb
SELA: 0x0C, // 0x0: 1st 8Kb of plane 2; 0x4: 2nd 8Kb; 0x8: 3rd 8Kb; 0xC: 4th 8Kb
SELB_HIGH: 0x10, // VGA only
SELA_HIGH: 0x20 // VGA only
},
MEMMODE: {
INDX: 0x04, // Sequencer Memory Mode Register
ALPHA: 0x01, // set for alphanumeric (A/N) mode, clear for graphics (APA or "All Points Addressable") mode (EGA only)
EXT: 0x02, // set if memory expansion installed, clear if not installed
SEQUENTIAL: 0x04, // set for sequential memory access, clear for mapping even addresses to planes 0/2, odd addresses to planes 1/3
CHAIN4: 0x08 // VGA only: set to select memory map (plane) based on low 2 bits of address
},
TOTAL_REGS: 0x05
};
if (DEBUGGER) Card.SEQ.REGS = ["RESET","CLOCKING","MAPMASK","CHARMAP","MEMMODE"];
/*
* VGA Digital-to-Analog Converter (DAC) Registers (regDACMask, regDACState, regDACAddr, and regDACData)
*
* To write DAC data, write an address to DAC.ADDR.PORT_WRITE, then write 3 bytes to DAC.DATA.PORT; the low 6 bits
* of each byte will be concatenated to form an 18-bit DAC value (red is least significant, followed by green, then blue).
* When the final byte is received, the 18-bit DAC value is updated and regDACAddr is auto-incremented.
*
* To read DAC data, the process is similar, but the initial address is written to DAC.ADDR.PORT_READ instead.
*
* DAC.STATE.PORT and DAC.ADDR.PORT_WRITE can be read at any time and will not interfere with a read or write operation
* in progress. To prevent "snow", reading or writing DAC values should be limited to retrace intervals (see regStatus1),
* or by using the SCREEN_OFF bit in the SEQ.CLOCKING register.
*/
Card.DAC = {
MASK: {
PORT: 0x3C6, // initialized to 0xFF and should not be changed
DEFAULT: 0xFF
},
STATE: {
PORT: 0x3C7,
MODE_WRITE: 0x00, // the DAC is in write mode if bits 0 and 1 are clear
MODE_READ: 0x03 // the DAC is in read mode if bits 0 and 1 are set
},
ADDR: {
PORT_READ: 0x3C7, // write to initiate a read
PORT_WRITE: 0x3C8 // write to initiate a write; read to determine the current ADDR
},
DATA: {
PORT: 0x3C9
},
TOTAL_REGS: 0x100
};
/*
* EGA/VGA Graphics Controller Registers (ports 0x3CE/0x3CF: regGRCIndx and regGRCData)
*
* The VGA added Write Mode 3, which is described as follows:
*
* "Each map is written with 8 bits of the value contained in the Set/Reset register for that map
* (the Enable Set/Reset register has no effect). Rotated system microprocessor data is ANDed with the
* Bit Mask register data to form an 8-bit value that performs the same function as the Bit Mask register
* does in write modes 0 and 2."
*/
Card.GRC = {
POS1_PORT: 0x3CC, // EGA only, write-only
POS2_PORT: 0x3CA, // EGA only, write-only
INDX: {
PORT: 0x3CE, // GRC Index Port
MASK: 0x0F
},
DATA: {
PORT: 0x3CF // GRC Data Port
},
SRESET: {
INDX: 0x00 // GRC Set/Reset Register (write-only; each bit used only if WRITE.MODE0 and corresponding ESR bit set)
},
ESRESET: {
INDX: 0x01 // GRC Enable Set/Reset Register
},
COLORCMP: {
INDX: 0x02 // GRC Color Compare Register
},
DATAROT: {
INDX: 0x03, // GRC Data Rotate Register
COUNT: 0x07,
AND: 0x08,
OR: 0x10,
XOR: 0x18,
FUNC: 0x18,
MASK: 0x1F
},
READMAP: {
INDX: 0x04, // GRC Read Map Select Register
NUM: 0x03
},
MODE: {
INDX: 0x05, // GRC Mode Register
WRITE: {
MODE0: 0x00, // write mode 0: each plane written with CPU data, rotated as needed, unless SR enabled
MODE1: 0x01, // write mode 1: each plane written with contents of the processor latches (loaded by a read)
MODE2: 0x02, // write mode 2: memory plane N is written with 8 bits matching data bit N
MODE3: 0x03, // write mode 3: VGA only
MASK: 0x03
},
TEST: 0x04,
READ: {
MODE0: 0x00, // read mode 0: read map mode
MODE1: 0x08, // read mode 1: color compare mode
MASK: 0x08
},
EVENODD: 0x10,
SHIFT: 0x20,
COLOR256: 0x40 // VGA only
},
MISC: {
INDX: 0x06, // GRC Miscellaneous Register
GRAPHICS: 0x01, // set for graphics mode addressing, clear for text mode addressing
CHAIN: 0x02, // set for odd/even planes selected with odd/even values of the processor AO bit
MAPMEM: 0x0C, //
MAPA0128: 0x00, //
MAPA064: 0x04, //
MAPB032: 0x08, //
MAPB832: 0x0C //
},
COLORDC: {
INDX: 0x07 // GRC Color "Don't Care" Register
},
BITMASK: {
INDX: 0x08 // GRC Bit Mask Register
},
TOTAL_REGS: 0x09
};
if (DEBUGGER) Card.GRC.REGS = ["SRESET","ESRESET","COLORCMP","DATAROT","READMAP","MODE","MISC","COLORDC","BITMASK"];
/*
* EGA Memory Access Functions
*
* Here's where we define all the getMemoryAccess() functions that know how to deal with "planar" EGA memory,
* which consists of 32-bit values for every byte of address space, allowing us to internally store plane 0
* bytes in bits 0-7, plane 1 bytes in bits 8-15, plane 2 bytes in bits 16-23, and plane 3 bytes in bits 24-31.
*
* All our functions have slightly more overhead than the standard Bus memory access functions, because the
* offset (off) parameter is block-relative, which we must transform into a buffer-relative offset. Fortunately,
* all our Memory objects know this and have already recorded their buffer-relative offset in "this.offset".
*
* Also, the EGA includes a set of latches, one for each plane, which must be updated on most reads/writes;
* we rely on the Memory object's "this.controller" property to give us access to the Card's state.
*
* And we take a little extra time to conditionally set fDirty on writes, meaning if a write did not actually
* change the value of the memory, we will not set fDirty. The default write functions in memory.js don't take
* that performance hit, but here, it may be worthwhile, because if it results in fewer dirty blocks, display
* updates may be faster.
*
* Note that we don't have to worry about dealing with word accesses that straddle block boundaries, because
* the Bus component automatically breaks those accesses into separate byte requests. Similarly, byte and word
* values for the write functions have already been pre-masked by the Bus component to 8 and 16 bits, respectively.
*
* My motto: Be paranoid, but also be careful not to do any more work than you absolutely have to.
*
*
* CGA Emulation on the EGA
*
* Modes 4/5 (320x200 low-res graphics) emulate the same buffer format that the CGA uses. To recap: 1 byte contains
* 4 pixels (pixel 0 in bits 7-6, pixel 1 in bits 5-4, etc), and thus one row of pixels is 80 (0x50) bytes long.
* Moreover, all even rows are stored in the first 8K of the video buffer (at 0xB8000), and all odd rows are stored
* in the second 8K (at 0xBA000). Of each 8K, only 8000 (0x1F40) bytes are used (80 bytes X 100 rows); the remaining
* 192 bytes of each 8K are unused.
*
* For these modes, the EGA's GRC.MODE is programmed with 0x30: Card.GRC.MODE.EVENODD and Card.GRC.MODE.SHIFT.
* The latter claims to work by forming each 2-bit pixel with even bits from plane 0 and odd bits from plane 1;
* however, I'm unclear how that works if even bytes are only written to plane 0 and odd bytes are only written to
* plane 1, as Card.GRC.MODE.EVENODD implies, because plane 0 would never have any bits for the odd bytes, and
* plane 1 would never have any bits for the even bytes. TODO: Figure this out.
*
*
* Even/Odd Memory Access Functions
*
* The "EVENODD" functions deal with the EGA's default text-mode addressing, where EVEN addresses are mapped to
* plane 0 (and 2) and ODD addresses are mapped to plane 1 (and 3). This occurs when SEQ.MEMMODE.SEQUENTIAL is
* clear (and GRC.MODE.EVENODD is set), turning address bit 0 (A0) into a "plane select" bit. Whether A0 is also
* used as a memory address bit depends on CRTC.MODE_CTRL.BYTE_MODE: if it's set, then we're in "Byte Mode" and A0 is
* used as-is; if it's clear, then we're in "Word Mode", and either A15 (when CRTC.MODE_CTRL.ADDR_WRAP is set) or A13
* (when CRTC.MODE_CTRL.ADDR_WRAP is clear, typically when only 64Kb of EGA memory is installed) is substituted for A0.
*
* Note that A13 remains clear until addresses reach 8K, at which point we've spanned 32Kb of EGA memory, so it makes
* sense to propagate A13 to A0 at that point, so that the next 8K of addresses start using ODD instead of EVEN bytes,
* and no memory is wasted on a 64Kb EGA card.
*
* These functions, however, don't yet deal with all those subtleties: A0 is currently used only as a "plane select"
* bit and set to zero for addressing purposes, meaning that only the EVEN bytes in EGA memory will ever be used.
* TODO: Implement the subtleties.
*/
/*
* Values returned by getCardAccess(); the high byte describes the read mode, and the low byte describes the write mode.
*
* V2 should never appear in any values used by getCardAccess() or setCardAccess(); the sole purpose of V2 is to
* distinguish newer (V2) access values from older (V1) access values in saved contexts. It's set when the context
* is saved, and cleared when the context is restored. Thus, if V2 is not set on restore, we assume we're dealing with
* a V1 value, so we run it through the V1 table (below) to produce a V2 value. Hopefully at some point V1 contexts
* can be deprecated, and the V2 bit can be eliminated/repurposed.
*/
Card.ACCESS = {
READ: { // READ values are designed to be OR'ed with WRITE values
MODE0: 0x0400,
MODE1: 0x0500,
EVENODD: 0x1000,
CHAIN4: 0x4000,
MASK: 0xFF00
},
WRITE: { // and WRITE values are designed to be OR'ed with READ values
MODE0: 0x0000,
MODE1: 0x0001,
MODE2: 0x0002,
MODE3: 0x0003, // VGA only
CHAIN4: 0x0004,
EVENODD: 0x0010,
ROT: 0x0020,
AND: 0x0060,
OR: 0x00A0,
XOR: 0x00E0,
MASK: 0x00FF
},
V2: (0x80000000|0) // this is a signature bit used ONLY to differentiate V2 access values from V1
};
/*
* Table of older (V1) access values and their corresponding new values; the new values are similar but more orthogonal
*/
Card.ACCESS.V1 = [];
Card.ACCESS.V1[0x0002] = Card.ACCESS.READ.MODE0;
Card.ACCESS.V1[0x0003] = Card.ACCESS.READ.MODE0 | Card.ACCESS.READ.EVENODD;
Card.ACCESS.V1[0x0010] = Card.ACCESS.READ.MODE1;
Card.ACCESS.V1[0x0200] = Card.ACCESS.WRITE.MODE0;
Card.ACCESS.V1[0x0400] = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.ROT;
Card.ACCESS.V1[0x0600] = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.AND;
Card.ACCESS.V1[0x0A00] = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.OR;
Card.ACCESS.V1[0x0E00] = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.XOR;
Card.ACCESS.V1[0x0300] = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.EVENODD;
Card.ACCESS.V1[0x1000] = Card.ACCESS.WRITE.MODE1;
Card.ACCESS.V1[0x2000] = Card.ACCESS.WRITE.MODE2;
Card.ACCESS.V1[0x6000] = Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.AND;
Card.ACCESS.V1[0xA000] = Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.OR;
Card.ACCESS.V1[0xE000] = Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.XOR;
/**
* readByteMode0(off, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} [addr]
* @return {number}
*/
Card.ACCESS.readByteMode0 = function readByteMode0(off, addr)
{
off += this.offset;
var dw = this.controller.latches = this.adw[off];
return (dw >> this.controller.nReadMapShift) & 0xff;
};
/**
* readByteMode0Chain4(off, addr)
*
* See writeByteMode0Chain4 for a description of how writes are distributed across planes.
*
* @this {Memory}
* @param {number} off
* @param {number} [addr]
* @return {number}
*/
Card.ACCESS.readByteMode0Chain4 = function readByteMode0Chain4(off, addr)
{
var idw = (off & ~0x3) + this.offset;
var shift = (off & 0x3) << 3;
return ((this.controller.latches = this.adw[idw]) >> shift) & 0xff;
};
/**
* readByteMode0EvenOdd(off, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} [addr]
* @return {number}
*/
Card.ACCESS.readByteMode0EvenOdd = function readByteMode0EvenOdd(off, addr)
{
/*
* TODO: As discussed in getCardAccess(), we need to run some tests on real EGA/VGA hardware to determine
* exactly what gets latched (ie, from which address) when EVENODD is in effect. Whatever we learn may
* also dictate a special EVENODD function for READ.MODE1 as well.
*/
off += this.offset;
var idw = off & ~0x1;
var dw = this.controller.latches = this.adw[idw];
return (!(off & 1)? dw : (dw >> 8)) & 0xff;
};
/**
* readByteMode1(off, addr)
*
* This mode requires us to step through each of the 8 sets of 4 bits in the specified DWORD of video memory,
* returning a 1 wherever all 4 match the Color Compare (COLORCMP) Register and a 0 otherwise. An added wrinkle
* is that the Color Don't Care (COLORDC) Register can specify that any/all/none of the 4 bits must be ignored.
*
* We perform the comparison from most to least significant bit, because that matches how the nColorCompare and
* nColorDontCare masks are initialized; we could have gone either way, but this is more consistent with the rest
* of the component (eg, pixels are drawn across the screen from left to right, starting with the most significant
* bit of each byte).
*
* Also note that, while not well-documented, this mode also affects the internal latches, so we make sure those
* are updated as well.
*
* @this {Memory}
* @param {number} off
* @param {number} [addr]
* @return {number}
*/
Card.ACCESS.readByteMode1 = function readByteMode1(off, addr)
{
off += this.offset;
var dw = this.controller.latches = this.adw[off];
/*
* Minor optimization: we could pre-mask nColorCompare with nColorDontCare, whenever either register
* is updated, but that's a drop in the bucket compared to all the other work this function must do.
*/
var mask = this.controller.nColorDontCare;
var color = this.controller.nColorCompare & mask;
var b = 0, bit = 0x80;
while (bit) {
if ((dw & mask) == color) b |= bit;
color >>>= 1; mask >>>= 1; bit >>= 1;
}
return b;
};
/**
* writeByteMode0(off, b, addr)
*
* Supporting Set/Reset means that for every plane for which Set/Reset is enabled, we must
* replace the corresponding byte in dw with a byte of zeros or ones. This is accomplished with
* nSetMapMask, nSetMapData, and nSetMapBits. nSetMapMask is the inverse of the ESRESET bits,
* because we use it to mask the processor data, nSetMapData records the desired SRESET bits,
* and nSetMapBits contains the bits to replace those that we masked in the processor data.
*
* We could have done this:
*
* dw = (dw & this.controller.nSetMapMask) | (this.controller.nSetMapData & ~this.controller.nSetMapMask)
*
* but by maintaining nSetMapBits equal to (nSetMapData & ~nSetMapMask), we are able to make
* the writes slightly more efficient.
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode0 = function writeByteMode0(off, b, addr)
{
var idw = off + this.offset;
var dw = b | (b << 8) | (b << 16) | (b << 24);
dw = (dw & this.controller.nSetMapMask) | this.controller.nSetMapBits;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode0(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode0Chain4(off, b, addr)
*
* This is how we distribute writes of 0xff across the address space to the planes (assuming that all
* planes are enabled by the Sequencer's MAPMASK register):
*
* off idw adw[idw]
* ------ ------ ----------
* 0x0000: 0x0000 0x000000ff
* 0x0001: 0x0000 0x0000ff00
* 0x0002: 0x0000 0x00ff0000
* 0x0003: 0x0000 0xff000000
* 0x0004: 0x0004 0x000000ff
* 0x0005: 0x0004 0x0000ff00
* 0x0006: 0x0004 0x00ff0000
* 0x0007: 0x0004 0xff000000
* ...
*
* Some VGA emulations calculate the video buffer index (idw) by shifting the offset (off) right 2 bits,
* instead of simply masking off the low 2 bits, as we do here. That would be a more "pleasing" arrangement,
* because we would be using sequential video buffer locations, instead of multiples of 4, and would match how
* pixels are stored in "Mode X". However, I don't think that's how CHAIN4 modes operate (although that still
* needs to be confirmed, because multiple sources conflict on this point). TODO: Confirm CHAIN4 operation on
* actual VGA hardware, including the extent to which ALU and other writeByteMode0() functionality needs to
* be folded into this.
*
* Address decoding may not matter that much, as long as both the read and write CHAIN4 functions decode their
* addresses in exactly the same manner; we'd only get into trouble with software that "unchained" or otherwise
* reconfigured the planes and then made assumptions about existing data in the video buffer.
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode0Chain4 = function writeByteMode0Chain4(off, b, addr)
{
var idw = (off & ~0x3) + this.offset;
var shift = (off & 0x3) << 3;
/*
* TODO: Consider adding a separate "unmasked" version of this CHAIN4 write function when nSeqMapMask is -1
* (or removing nSeqMapMask from the equation altogether, if CHAIN4 is never used with any planes disabled).
*/
var dw = ((b << shift) & this.controller.nSeqMapMask) | (this.adw[idw] & ~((0xff << shift) & this.controller.nSeqMapMask));
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode0Chain4(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode0EvenOdd(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode0EvenOdd = function writeByteMode0EvenOdd(off, b, addr)
{
off += this.offset;
var dw = b | (b << 8) | (b << 16) | (b << 24);
/*
* When even/odd addressing is enabled, nSeqMapMask must be cleared for planes 1
* and 3 if the address is even, and cleared for planes 0 and 2 if the address is odd.
*/
var idw = off & ~0x1;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
var maskMaps = this.controller.nSeqMapMask & (idw == off? 0x00ff00ff : (0xff00ff00|0));
dw = (dw & maskMaps) | (this.adw[idw] & ~maskMaps);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode0EvenOdd(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode0Rot(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode0Rot = function writeByteMode0Rot(off, b, addr)
{
var idw = off + this.offset;
b = ((b >> this.controller.nDataRotate) | (b << (8 - this.controller.nDataRotate)) & 0xff);
var dw = b | (b << 8) | (b << 16) | (b << 24);
dw = (dw & this.controller.nSetMapMask) | this.controller.nSetMapBits;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode0Rot(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode0And(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode0And = function writeByteMode0And(off, b, addr)
{
var idw = off + this.offset;
b = ((b >> this.controller.nDataRotate) | (b << (8 - this.controller.nDataRotate)) & 0xff);
var dw = b | (b << 8) | (b << 16) | (b << 24);
dw = (dw & this.controller.nSetMapMask) | this.controller.nSetMapBits;
dw &= this.controller.latches;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode0And(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode0Or(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode0Or = function writeByteMode0Or(off, b, addr)
{
var idw = off + this.offset;
b = ((b >> this.controller.nDataRotate) | (b << (8 - this.controller.nDataRotate)) & 0xff);
var dw = b | (b << 8) | (b << 16) | (b << 24);
dw = (dw & this.controller.nSetMapMask) | this.controller.nSetMapBits;
dw |= this.controller.latches;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode0Or(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode0Xor(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode0Xor = function writeByteMode0Xor(off, b, addr)
{
var idw = off + this.offset;
b = ((b >> this.controller.nDataRotate) | (b << (8 - this.controller.nDataRotate)) & 0xff);
var dw = b | (b << 8) | (b << 16) | (b << 24);
dw = (dw & this.controller.nSetMapMask) | this.controller.nSetMapBits;
dw ^= this.controller.latches;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode0Xor(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode1(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (ignored; the EGA latches provide the source data)
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode1 = function writeByteMode1(off, b, addr)
{
var idw = off + this.offset;
var dw = (this.adw[idw] & ~this.controller.nSeqMapMask) | (this.controller.latches & this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode1(" + str.toHexLong(addr) + "): " + str.toHexLong(dw));
}
};
/**
* writeByteMode1EvenOdd(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (ignored; the EGA latches provide the source data)
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode1EvenOdd = function writeByteMode1EvenOdd(off, b, addr)
{
/*
* TODO: As discussed in getCardAccess(), we need to run some tests on real EGA/VGA hardware to
* determine exactly where latches are written (ie, to which address) when EVENODD is in effect.
*/
off += this.offset;
//
// When even/odd addressing is enabled, nSeqMapMask must be cleared for planes 1 and 3 if
// the address is even, and cleared for planes 0 and 2 if the address is odd.
//
var idw = off & ~0x1;
var maskMaps = this.controller.nSeqMapMask & (idw == off? 0x00ff00ff : (0xff00ff00|0));
var dw = (this.adw[idw] & ~maskMaps) | (this.controller.latches & maskMaps);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode1EvenOdd(" + str.toHexLong(addr) + "): " + str.toHexByte(dw));
}
};
/**
* writeByteMode2(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode2 = function writeByteMode2(off, b, addr)
{
var idw = off + this.offset;
var dw = Video.aEGAByteToDW[b & 0xf];
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode2(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode2And(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode2And = function writeByteMode2And(off, b, addr)
{
var idw = off + this.offset;
var dw = Video.aEGAByteToDW[b & 0xf];
dw &= this.controller.latches;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode2And(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode2Or(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode2Or = function writeByteMode2Or(off, b, addr)
{
var idw = off + this.offset;
var dw = Video.aEGAByteToDW[b & 0xf];
dw |= this.controller.latches;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode2Or(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode2Xor(off, b, addr)
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode2Xor = function writeByteMode2Xor(off, b, addr)
{
var idw = off + this.offset;
var dw = Video.aEGAByteToDW[b & 0xf];
dw ^= this.controller.latches;
dw = (dw & this.controller.nBitMapMask) | (this.controller.latches & ~this.controller.nBitMapMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode2Xor(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/**
* writeByteMode3(off, b, addr)
*
* In MODE3, Set/Reset is always enabled, so the ESRESET bits (and therefore nSetMapMask and nSetMapBits)
* are ignored; we look only at the SRESET bits, which are stored in nSetMapData.
*
* Unlike MODE0, we currently have no non-rotate function for MODE3. If performance dictates, we can add one;
* ditto for other features like the Sequencer's MAPMASK register (nSeqMapMask).
*
* @this {Memory}
* @param {number} off
* @param {number} b (which should already be pre-masked to 8 bits; see cpu.setByte())
* @param {number} [addr]
*/
Card.ACCESS.writeByteMode3 = function writeByteMode3(off, b, addr)
{
var idw = off + this.offset;
b = ((b >> this.controller.nDataRotate) | (b << (8 - this.controller.nDataRotate)) & 0xff);
var dw = b | (b << 8) | (b << 16) | (b << 24);
var dwMask = (dw & this.controller.nBitMapMask);
dw = (this.controller.nSetMapData & dwMask) | (this.controller.latches & ~dwMask);
dw = (dw & this.controller.nSeqMapMask) | (this.adw[idw] & ~this.controller.nSeqMapMask);
if (this.adw[idw] != dw) {
this.adw[idw] = dw;
this.fDirty = true;
}
if (DEBUG && this.controller.video.messageEnabled(Messages.MEM | Messages.VIDEO)) {
this.controller.video.printMessage("writeByteMode3(" + str.toHexLong(addr) + "): " + str.toHexByte(b) + " -> " + str.toHexLong(dw));
}
};
/*
* Mappings from getCardAccess() values to access functions above
*/
Card.ACCESS.afn = [];
Card.ACCESS.afn[Card.ACCESS.READ.MODE0] = Card.ACCESS.readByteMode0;
Card.ACCESS.afn[Card.ACCESS.READ.MODE0 | Card.ACCESS.READ.CHAIN4] = Card.ACCESS.readByteMode0Chain4;
Card.ACCESS.afn[Card.ACCESS.READ.MODE0 | Card.ACCESS.READ.EVENODD] = Card.ACCESS.readByteMode0EvenOdd;
Card.ACCESS.afn[Card.ACCESS.READ.MODE1] = Card.ACCESS.readByteMode1;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE0] = Card.ACCESS.writeByteMode0;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.ROT] = Card.ACCESS.writeByteMode0Rot;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.AND] = Card.ACCESS.writeByteMode0And;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.OR] = Card.ACCESS.writeByteMode0Or;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.XOR] = Card.ACCESS.writeByteMode0Xor;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.CHAIN4] = Card.ACCESS.writeByteMode0Chain4;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.EVENODD] = Card.ACCESS.writeByteMode0EvenOdd;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE1] = Card.ACCESS.writeByteMode1;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE1 | Card.ACCESS.WRITE.EVENODD] = Card.ACCESS.writeByteMode1EvenOdd;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE2] = Card.ACCESS.writeByteMode2;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.AND] = Card.ACCESS.writeByteMode2And;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.OR] = Card.ACCESS.writeByteMode2Or;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.XOR] = Card.ACCESS.writeByteMode2Xor;
Card.ACCESS.afn[Card.ACCESS.WRITE.MODE3] = Card.ACCESS.writeByteMode3;
/**
* initEGA(data)
*
* Another one of my frustrations with JSON is that it encodes empty arrays with non-zero lengths as
* arrays of nulls, which means that any uninitialized register arrays whose elements were all originally
* undefined come back via the JSON round-trip as *initialized* arrays whose elements are now all null.
*
* I'm a bit surprised, because JavaScript purists tell us to always use the '===' operator (eg, use
* 'aReg[i] === undefined' to determine if an element is initialized), but because of this JSON stupidity,
* that would require all such tests to become 'aReg[i] === undefined || aReg[i] === null'. I'm puzzled
* why the coercion of '==' is considered evil but JSON's coercion of undefined to null is perfectly fine.
*
* The simple solution is to change such comparisons to 'aReg[i] == null', because undefined is coerced
* to null, whereas numeric values are not.
*
* [What do I mean by "another" frustration? Let me talk to you some day about disallowing hex constants,
* or insisting that property names be quoted, or refusing to allow comments. I think it's fine for
* JSON.stringify() to produce output that adheres to rules like that -- although some parameters to control
* the output would be nice -- but it's completely unnecessary for JSON.parse() to refuse to parse objects
* that are perfectly valid.]
*
* @this {Card}
* @param {Array|undefined} data
* @param {number} nMonitorType
*/
Card.prototype.initEGA = function(data, nMonitorType)
{
if (data === undefined) {
data = [
/* 0*/ false,
/* 1*/ 0,
/* 2*/ new Array(Card.ATC.TOTAL_REGS),
/* 3*/ 0,
/* 4*/ (nMonitorType == ChipSet.MONITOR.MONO? 0: Card.MISC.IO_SELECT),
/* 5*/ 0,
/* 6*/ 0,
/* 7*/ new Array(Card.SEQ.TOTAL_REGS),
/* 8*/ 0,
/* 9*/ 0,
/*10*/ 0,
/*11*/ new Array(Card.GRC.TOTAL_REGS),
/*12*/ 0,
/*13*/ [this.addrBuffer, this.sizeBuffer, this.cbMemory],
/*14*/ new Array(this.cbMemory >> 2), // divide cbMemory by 4 since this is an array of DWORDs (8 bits for each of 4 planes)
/*
* Card.ACCESS.WRITE.MODE0 by itself is a pretty good default, but if we choose to "randomize" the screen with
* text characters prior to starting the machine, defaulting to Card.ACCESS.WRITE.EVENODD is more faithful to how
* characters and attributes are typically stored (ie, in planes 0 and 1, respectively). As soon as the machine
* starts up and initializes the hardware itself, these defaults won't matter.
*/
/*15*/ Card.ACCESS.READ.MODE0 | Card.ACCESS.READ.EVENODD | Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.EVENODD | Card.ACCESS.V2,
/*16*/ 0,
/*17*/ 0xffffffff|0,
/*18*/ 0,
/*19*/ 0xffffffff|0,
/*20*/ 0,
/*21*/ 0xffffffff|0,
/*22*/ 0,
/*23*/ 0,
/*24*/ 0,
/*25*/ 0,
/*26*/ Card.VGA_ENABLE.ENABLED,
/*27*/ Card.DAC.MASK.DEFAULT,
/*28*/ 0,
/*29*/ 0,
/*30*/ Card.DAC.STATE.MODE_WRITE,
/*31*/ new Array(Card.DAC.TOTAL_REGS)
];
}
this.fATCData = data[0];
this.regATCIndx = data[1];
this.regATCData = data[2];
this.asATCRegs = DEBUGGER? Card.ATC.REGS : [];
this.regStatus0 = data[3]; // aka STATUS0 (not to be confused with this.regStatus, which the EGA refers to as STATUS1)
this.regMisc = data[4];
this.regFeat = data[5]; // for feature control bits, see Card.FEAT_CTRL.BITS; for feature status bits, see Card.STATUS0.FEAT
this.regSEQIndx = data[6];
this.regSEQData = data[7];
this.asSEQRegs = DEBUGGER? Card.SEQ.REGS : [];
this.regGRCPos1 = data[8];
this.regGRCPos2 = data[9];
this.regGRCIndx = data[10];
this.regGRCData = data[11];
this.asGRCRegs = DEBUGGER? Card.GRC.REGS : [];
this.latches = data[12];
/*
* Since we originally neglected to save/restore the card's active video buffer address and length,
* we're now stashing all that information in data[13]. So if we're presented with an old data entry
* that contains only the card's memory size, fix it up.
*
* TODO: This code just creates the required array; the correct video buffer address and length would
* still need to be calculated from the current GRC registers; checkMode() knows how to do that, but I'm
* not prepared to shoehorn in a call to checkMode() here, and potentially create more issues, for an
* old problem that will eventually disappear anyway.
*/
var a = data[13];
if (typeof a == "number") {
a = [this.addrBuffer, this.sizeBuffer, a];
}
this.addrBuffer = a[0];
this.sizeBuffer = a[1];
this.video.assert(this.cbMemory === a[2]);
var cdw = this.cbMemory >> 2;
this.adwMemory = data[14];
if (this.adwMemory && this.adwMemory.length < cdw) {
this.adwMemory = State.decompressEvenOdd(this.adwMemory, cdw);
}
var nAccess = data[15];
if (nAccess) {
if (nAccess & Card.ACCESS.V2) {
nAccess &= ~Card.ACCESS.V2;
} else {
this.video.assert(Card.ACCESS.V1[nAccess & 0xff00] !== undefined && Card.ACCESS.V1[nAccess & 0xff] !== undefined);
nAccess = Card.ACCESS.V1[nAccess & 0xff00] | Card.ACCESS.V1[nAccess & 0xff];
}
}
this.setMemoryAccess(nAccess);
/*
* nReadMapShift must perfectly track how the GRC.READMAP register is programmed, so that Card.ACCESS.READ.MODE0
* memory read functions read the appropriate plane. This default is not terribly critical, unless Card.ACCESS.WRITE.MODE0
* is chosen as our default AND you want the screen randomizer to work.
*/
this.nReadMapShift = data[16];
/*
* Similarly, nSeqMapMask must perfectly track how the SEQ.MAPMASK register is programmed, so that memory write
* functions write the appropriate plane(s). Again, this default is not terribly critical, unless Card.ACCESS.WRITE.MODE0
* is chosen as our default AND you want the screen randomizer to work.
*/
this.nSeqMapMask = data[17];
this.nDataRotate = data[18];
this.nBitMapMask = data[19];
this.nSetMapData = data[20];
this.nSetMapMask = data[21];
this.nSetMapBits = data[22];
this.nColorCompare = data[23];
this.nColorDontCare = data[24];
this.offStartAddr = data[25]; // this is the last CRTC start address latched from CRTC.START_ADDR_HI,CRTC.START_ADDR_LO
this.nVertPeriods = this.nVertPeriodsStartAddr = 0;
if (this.nCard == Video.CARD.VGA) {
this.regVGAEnable = data[26];
this.regDACMask = data[27];
this.regDACAddr = data[28];
this.regDACShift = data[29];
this.regDACState = data[30];
this.regDACData = data[31];
}
};
/**
* saveCard()
*
* @this {Card}
* @return {Array}
*/
Card.prototype.saveCard = function()
{
var data = [];
if (this.nCard !== undefined) {
data[0] = this.fActive;
data[1] = this.regMode;
data[2] = this.regColor;
data[3] = this.regStatus;
data[4] = this.regCRTIndx | (this.regCRTPrev << 8);
data[5] = this.regCRTData;
if (this.nCard >= Video.CARD.EGA) {
data[6] = this.saveEGA();
}
data[7] = this.nInitCycles;
}
return data;
};
/**
* saveEGA()
*
* @this {Card}
* @return {Array}
*/
Card.prototype.saveEGA = function()
{
var data = [];
data[0] = this.fATCData;
data[1] = this.regATCIndx;
data[2] = this.regATCData;
data[3] = this.regStatus0;
data[4] = this.regMisc;
data[5] = this.regFeat;
data[6] = this.regSEQIndx;
data[7] = this.regSEQData;
data[8] = this.regGRCPos1;
data[9] = this.regGRCPos2;
data[10] = this.regGRCIndx;
data[11] = this.regGRCData;
data[12] = this.latches;
data[13] = [this.addrBuffer, this.sizeBuffer, this.cbMemory];
data[14] = State.compressEvenOdd(this.adwMemory);
data[15] = this.nAccess | Card.ACCESS.V2;
data[16] = this.nReadMapShift;
data[17] = this.nSeqMapMask;
data[18] = this.nDataRotate;
data[19] = this.nBitMapMask;
data[20] = this.nSetMapData;
data[21] = this.nSetMapMask;
data[22] = this.nSetMapBits;
data[23] = this.nColorCompare;
data[24] = this.nColorDontCare;
data[25] = this.offStartAddr;
if (this.nCard == Video.CARD.VGA) {
data[26] = this.regVGAEnable;
data[27] = this.regDACMask;
data[28] = this.regDACAddr;
data[29] = this.regDACShift;
data[30] = this.regDACState;
data[31] = this.regDACData;
}
return data;
};
/**
* dumpRegs()
*
* Since we don't pre-allocate the register arrays (eg, ATC, CRTC, GRC, etc) on a Card, we can't
* rely on their array length, so we instead rely on the number of register names supplied in asRegs.
*
* @this {Card}
* @param {string} sName
* @param {number} iReg
* @param {Array} [aRegs]
* @param {Array} [asRegs]
*/
Card.prototype.dumpRegs = function(sName, iReg, aRegs, asRegs)
{
if (DEBUGGER) {
if (!aRegs) {
this.dbg.println(sName + ": " + str.toHex(iReg, 2));
return;
}
var i, cchMax = 18, s = "";
for (i = 0; i < asRegs.length; i++) {
var reg = (aRegs === this.regCRTData)? this.getCRTCReg(i) : aRegs[i];
if (s) s += '\n';
s += sName + "[" + str.toHex(i, 2) + "]: " + str.pad(asRegs[i], cchMax) + (i === iReg? '*' : ' ') + str.toHex(reg, reg > 0xff? 4 : 2);
if (reg != null) s += " (" + reg + ".)"
}
this.dbg.println(s);
}
};
/**
* dumpVideoCard()
*
* @this {Card}
*/
Card.prototype.dumpVideoCard = function()
{
if (DEBUGGER) {
/*
* Start with registers that are common to all cards....
*/
this.dumpRegs("CRTC", this.regCRTIndx, this.regCRTData, this.asCRTCRegs);
if (this.nCard >= Video.CARD.EGA) {
this.dumpRegs(" GRC", this.regGRCIndx, this.regGRCData, this.asGRCRegs);
this.dumpRegs(" SEQ", this.regSEQIndx, this.regSEQData, this.asSEQRegs);
this.dumpRegs(" ATC", this.regATCIndx, this.regATCData, this.asATCRegs);
this.dumpRegs(" ATCINDX", this.regATCIndx);
this.dbg.println(" ATCDATA: " + this.fATCData);
this.dumpRegs(" FEAT", this.regFeat);
this.dumpRegs(" MISC", this.regMisc);
this.dumpRegs(" STATUS0", this.regStatus0);
/*
* There are few more EGA regs we could dump, like GRCPos1, GRCPos2, but does anyone care?
*/
}
/*
* TODO: This simply dumps the last value read from the STATUS1 register, not necessarily
* its current state; consider dumping getRetraceBits() instead of (or in addition to) this.
*/
this.dumpRegs(" STATUS1", this.regStatus);
if (this.nCard == Video.CARD.MDA || this.nCard == Video.CARD.CGA) {
this.dumpRegs(" MODEREG", this.regMode);
}
if (this.nCard == Video.CARD.CGA) {
this.dumpRegs(" COLOR", this.regColor);
}
if (this.nCard >= Video.CARD.EGA) {
this.dbg.println(" LATCHES: " + str.toHex(this.latches));
this.dbg.println(" ACCESS: " + str.toHex(this.nAccess, 4));
this.dbg.println("Use 'dump video [addr]' to dump video memory");
/*
* There are few more EGA regs we could dump, like GRCPos1, GRCPos2, but does anyone care?
*/
}
}
};
/**
* dumpVideoBuffer(asArgs)
*
* Rather than requiring the first parameter to ALWAYS be a frame buffer address OR a frame buffer
* offset, we'll just make a guess as to what the user intended and support BOTH; basically, if the
* value is less than the frame buffer address, we'll assume it's an offset.
*
* Also, we allow some special options to be encoded in asArgs: 'l' followed by a number means
* print that many rows of data. 'n' followed by a number (1-8) means print only that number of
* memory locations per row, and then adjust the starting address of the next row by the number
* of bytes per row (or whatever is specified by the 'w' option) so that the dump reflects a
* rectangular chunk of video data. Finally, if asArgs contains 'p' followed by a number (0-3),
* we display only the bits from that plane for each memory location, in binary instead of hex.
*
* For example, assuming a standard VGA frame buffer with 640x480 pixels across 38400 (0x9600) memory
* locations, the following command will dump a vertical swath of bits from plane 0 that is 32 (0x20)
* rows tall and 8 columns wide, from roughly the center of the screen (0x4B00 + 0x28 - 2 = 0x4B26).
*
* d video 4b26 l20 n8 p0
*
* Subsequent commands that omit a starting address or offset will continue where the last dump
* left off; eg:
*
* d video n8 p0
*
* To dump a chunk of off-screen memory starting at 0x9600, where the Windows VGA driver typically
* stores a copy of the video memory containing the current mouse pointer:
*
* d video 9600 l20 n5 w5 p0
*
* Alternatively, you could use decimal values:
*
* d video 9600 l32. n5. w5. p0.
*
* NOTE: If these commands look suspiciously like weird Hayes modem command strings, trust me,
* that is ENTIRELY coincidental (but mildly amusing).
*
* TODO: Make these options more general-purpose (it currently assumes a conventional VGA planar layout).
*
* @this {Card}
* @param {Array.<string>} asArgs
*/
Card.prototype.dumpVideoBuffer = function(asArgs)
{
if (DEBUGGER) {
if (!this.adwMemory) {
this.dbg.println("no buffer");
return;
}
var i, j, idw, fColAdjust = false;
var l = 8, n = 8, p = -1, w = this.video.nCols >> 3;
for (i = 0; i < asArgs.length; i++) {
var s = asArgs[i];
if (!i) {
idw = str.parseInt(s);
continue;
}
var ch = s.charAt(0);
j = str.parseInt(s.substr(1));
switch(ch) {
case 'l':
l = j;
break;
case 'n':
if (j >= 1 && j <= 8) {
n = j;
fColAdjust = true;
}
break;
case 'p':
if (j >= 0 && j <= 3) p = j;
break;
case 'w':
if (j < w) w = j;
break;
default:
this.dbg.println("unrecognized argument: " + s);
break;
}
}
if (idw === undefined) {
idw = this.prevDump || 0;
} else if (idw >= this.addrBuffer) {
idw -= this.addrBuffer;
}
var sDump = "";
for (i = 0; i < l; i++) {
var sData = str.toHex(this.addrBuffer + idw) + ":";
for (j = 0; j < n && idw < this.adwMemory.length; j++) {
var dw = this.adwMemory[idw++];
sData += ' ' + ((p < 0)? str.toHex(dw) : str.toBin((dw >> (p << 3)), 8));
}
if (fColAdjust) idw += w - n;
if (sDump) sDump += "\n";
sDump += sData;
}
if (sDump) this.dbg.println(sDump);
this.prevDump = idw;
}
};
/**
* getMemoryBuffer(addr)
*
* If we passed a controller object (ie, this card) to addMemory(), then each allocated Memory block
* will call this function to obtain a buffer.
*
* @this {Card}
* @param {number} addr
* @return {Array} containing the buffer (and the offset within that buffer that corresponds to the requested block)
*/
Card.prototype.getMemoryBuffer = function(addr)
{
return [this.adwMemory, addr - this.addrBuffer];
};
/**
* getMemoryAccess()
*
* WARNING: This is a public method, whereas most Card methods are private to the Video component;
* because a Card also acts as a Memory controller, it must provide getMemoryAccess() to the Memory component.
*
* Return the last set of memory access functions recorded by setMemoryAccess().
*
* @this {Card}
* @return {Array.<function()>}
*/
Card.prototype.getMemoryAccess = function()
{
return this.afnAccess;
};
/**
* setMemoryAccess(nAccess)
*
* This transforms the memory access value that getCardAccess() returns into the best available set of
* memory access functions, which are then returned via getMemoryAccess() to any memory blocks we allocate
* or modify.
*
* @this {Card}
* @param {number|undefined} nAccess
*/
Card.prototype.setMemoryAccess = function(nAccess)
{
if (nAccess != null && nAccess != this.nAccess) {
var nReadAccess = nAccess & Card.ACCESS.READ.MASK;
var fnReadByte = Card.ACCESS.afn[nReadAccess];
if (!fnReadByte) {
if (DEBUG && this.dbg && this.dbg.messageEnabled(Messages.VIDEO)) {
this.dbg.message("Card.setMemoryAccess(" + str.toHexWord(nAccess) + "): missing readByte handler");
/*
* I've taken a look, and the cases I've seen so far stem from the order in which the IBM VGA BIOS
* reprograms registers during a mode change: it reprograms the Sequencer registers BEFORE the Graphics
* Controller registers, so if GRC.MODE was set to READ.MODE1 prior to the mode change and the new mode
* clears SEQ.MEMMODE.SEQUENTIAL, we will briefly be in an "odd" (unsupported) state.
*
* This didn't used to occur when we relied on the GRC.MODE register instead of the SEQ.MEMMODE for
* determining the EVENODD state. But, as explained in getCardAccess(), we've run into inconsistencies in
* how GRC.MODE.EVENODD is programmed, so we must live with this warning.
*
* The ultimate solution is to provide a EVENODD handler for READ.MODE1, since there is the remote
* possibility of third-party software that relies on that "odd" combination.
*
* this.dbg.stopCPU(); // let's take a look
*/
}
if (nReadAccess & Card.ACCESS.READ.EVENODD) {
fnReadByte = Card.ACCESS.afn[Card.ACCESS.READ.EVENODD];
}
}
var nWriteAccess = nAccess & Card.ACCESS.WRITE.MASK;
var fnWriteByte = Card.ACCESS.afn[nWriteAccess];
if (!fnWriteByte) {
if (DEBUG && this.dbg && this.dbg.messageEnabled(Messages.VIDEO)) {
this.dbg.message("Card.setMemoryAccess(" + str.toHexWord(nAccess) + "): missing writeByte handler");
/*
* I've taken a look, and the cases I've seen so far stem from the order in which the IBM VGA BIOS
* reprograms registers during a mode change: it reprograms the Sequencer registers BEFORE the Graphics
* Controller registers, so if GRC.MODE was set to WRITE.MODE2 prior to the mode change and the new mode
* clears SEQ.MEMMODE.SEQUENTIAL, we will briefly be in an "odd" (unsupported) state.
*
* This didn't used to occur when we relied on the GRC.MODE register instead of the SEQ.MEMMODE for
* determining the EVENODD state. But, as explained in getCardAccess(), we've run into inconsistencies in
* how GRC.MODE.EVENODD is programmed, so we must live with this warning.
*
* The ultimate solution is to provide EVENODD handlers for all modes other than WRITE.MODE0, since there
* is the remote possibility of third-party software that relies on one of those "odd" combinations.
*
* this.dbg.stopCPU(); // let's take a look
*/
}
if (nWriteAccess & Card.ACCESS.WRITE.EVENODD) {
fnWriteByte = Card.ACCESS.afn[Card.ACCESS.WRITE.EVENODD];
}
}
if (!this.afnAccess) this.afnAccess = new Array(6);
this.afnAccess[0] = fnReadByte;
this.afnAccess[3] = fnWriteByte;
this.nAccess = nAccess;
}
};
/**
* getCRTCReg()
*
* @this {Card}
* @param {number} iReg
* @return {number}
*/
Card.prototype.getCRTCReg = function(iReg)
{
var reg = this.regCRTData[iReg];
if (reg != null && this.nCard >= Video.CARD.EGA) {
var bOvrflowBit8 = 0, bOvrflowBit9 = 0, bMaxScanBit9 = 0;
switch(iReg) {
case Card.CRTC.EGA.VTOTAL: // 0x06
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.VTOTAL_BIT8; // 0x01
if (this.nCard == Video.CARD.VGA) bOvrflowBit9 = Card.CRTC.EGA.OVERFLOW.VTOTAL_BIT9;
break;
case Card.CRTC.EGA.CURSOR_START.INDX: // 0x0A
if (this.nCard == Video.CARD.EGA) bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.CURSOR_START_BIT8;
break;
case Card.CRTC.EGA.VRETRACE_START: // 0x10
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.VRETRACE_START_BIT8; // 0x04
if (this.nCard == Video.CARD.VGA) bOvrflowBit9 = Card.CRTC.EGA.OVERFLOW.VRETRACE_START_BIT9;
break;
case Card.CRTC.EGA.VDISP_END: // 0x12
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.VDISP_END_BIT8; // 0x02
if (this.nCard == Video.CARD.VGA) bOvrflowBit9 = Card.CRTC.EGA.OVERFLOW.VDISP_END_BIT9;
break;
case Card.CRTC.EGA.VBLANK_START: // 0x15
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.VBLANK_START_BIT8; // 0x08
if (this.nCard == Video.CARD.VGA) bMaxScanBit9 = Card.CRTC.EGA.MAX_SCAN.VBLANK_START_BIT9;
break;
case Card.CRTC.EGA.LINE_COMPARE: // 0x18
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.LINE_COMPARE_BIT8; // 0x10
if (this.nCard == Video.CARD.VGA) bMaxScanBit9 = Card.CRTC.EGA.MAX_SCAN.LINE_COMPARE_BIT9;
break;
}
if (bOvrflowBit8) {
reg |= ((this.regCRTData[Card.CRTC.EGA.OVERFLOW.INDX] & bOvrflowBit8)? 0x100 : 0);
reg |= ((this.regCRTData[Card.CRTC.EGA.OVERFLOW.INDX] & bOvrflowBit9)? 0x200 : 0);
reg |= ((this.regCRTData[Card.CRTC.EGA.MAX_SCAN.INDX] & bMaxScanBit9)? 0x200 : 0);
}
}
return reg;
};
/*
* Card Specifications
*
* We support dynamically switching between MDA and CGA cards by simply flipping switches on
* the virtual SW1 switch block and resetting the machine. However, I'm not sure I'll support
* dynamically switching the EGA card the same way; there's certainly no UI for it at this point.
*
* For each supported card, there is a cardSpec array that the Card class uses to initialize the
* card's defaults:
*
* [0]: card descriptor
* [1]: default CRTC port address
* [2]: default video buffer address
* [3]: default video buffer size
* [4]: total on-board memory (if no "memory" parm was specified)
* [5]: default monitor type
*
* If total on-board memory is zero, then addMemory() will simply add the specified video buffer
* to the address space; otherwise, we will allocate an internal buffer (adwMemory) and tell addMemory()
* to map it to the video buffer address. The latter approach gives us total control over the buffer;
* refer to getMemoryAccess().
*
* TODO: Consider allocating our own buffer for all video cards, not just EGA/VGA. For MDA/CGA, I'm not
* sure it would offer any benefits, other than allowing our internal update functions, like updateScreen(),
* to access the buffer directly, instead of going through the Bus memory interface.
*/
Video.cardSpecs = [];
Video.cardSpecs[Video.CARD.MDA] = ["MDA", Card.MDA.CRTC.INDX.PORT, 0xB0000, 0x01000, 0, ChipSet.MONITOR.MONO];
Video.cardSpecs[Video.CARD.CGA] = ["CGA", Card.CGA.CRTC.INDX.PORT, 0xB8000, 0x04000, 0, ChipSet.MONITOR.COLOR];
Video.cardSpecs[Video.CARD.EGA] = ["EGA", Card.CGA.CRTC.INDX.PORT, 0xB8000, 0x04000, 0x10000, ChipSet.MONITOR.EGACOLOR];
Video.cardSpecs[Video.CARD.VGA] = ["VGA", Card.CGA.CRTC.INDX.PORT, 0xB8000, 0x04000, 0x40000, ChipSet.MONITOR.VGACOLOR];
/*
* Values for nTouchConfig; a value will be selected based on the sTouchScreen configuration parameter.
*/
Video.TOUCH = {
NONE: 0,
KEYGRID: 1,
MOUSE: 2
};
/**
* initBus(cmp, bus, cpu, dbg)
*
* This is a notification issued by the Computer component, after all the other components (notably the CPU)
* have had a chance to initialize.
*
* @this {Video}
* @param {Computer} cmp
* @param {Bus} bus
* @param {X86CPU} cpu
* @param {Debugger} dbg
*/
Video.prototype.initBus = function(cmp, bus, cpu, dbg)
{
this.bus = bus;
this.cpu = cpu;
this.dbg = dbg;
/*
* nCard will be undefined if no model was explicitly set (whereas this.nCard is ALWAYS defined).
*/
var aModel = Video.MODEL[this.model], nCard = aModel && aModel[0];
/*
* The only time we do NOT want to trap MDA ports is when the model has been explicitly set to CGA.
*/
if (nCard !== Video.CARD.CGA) {
bus.addPortInputTable(this, Video.aMDAPortInput);
bus.addPortOutputTable(this, Video.aMDAPortOutput);
}
/*
* Similarly, the only time we do NOT want to trap CGA ports is when the model is explicitly set to MDA.
*/
if (nCard !== Video.CARD.MDA) {
bus.addPortInputTable(this, Video.aCGAPortInput);
bus.addPortOutputTable(this, Video.aCGAPortOutput);
}
/*
* Note that in the case of EGA and VGA models, the above code ensures that we will trap both MDA and CGA
* port ranges -- which is good, because both the EGA and VGA can be reprogrammed to respond to those ports,
* but also potentially bad if you want to simulate a "dual display" system, where one of the displays is
* driven by either an MDA or CGA.
*
* However, you should still be able to make that work by loading the MDA or CGA video component first, because
* components should be initialized in the order they appear in the machine configuration file. Any attempt
* by another component to trap the same ports should be ignored.
*/
if (this.nCard >= Video.CARD.EGA) {
bus.addPortInputTable(this, Video.aEGAPortInput);
bus.addPortOutputTable(this, Video.aEGAPortOutput);
}
if (this.nCard == Video.CARD.VGA) {
bus.addPortInputTable(this, Video.aVGAPortInput);
bus.addPortOutputTable(this, Video.aVGAPortOutput);
}
if (DEBUGGER && dbg) {
var video = this;
dbg.messageDump(Messages.VIDEO, function onDumpVideo(asArgs) {
video.dumpVideo(asArgs);
});
}
/*
* If we have an associated keyboard, then ensure that the keyboard will be notified whenever the canvas
* gets focus and receives input.
*/
this.kbd = cmp.getMachineComponent("Keyboard");
if (this.kbd && this.canvasScreen) {
for (var s in this.bindings) {
if (s.indexOf("lock") > 0) this.kbd.setBinding("led", s, this.bindings[s]);
}
this.kbd.setBinding(this.textareaScreen? "textarea" : "canvas", "kbd", this.inputScreen);
}
this.bEGASwitches = 0x09; // our default "switches" setting (see aEGAMonitorSwitches)
this.chipset = cmp.getMachineComponent("ChipSet");
if (this.chipset && this.sSwitches) {
if (this.nCard == Video.CARD.EGA) {
this.bEGASwitches = this.chipset.parseDIPSwitches(this.sSwitches, this.bEGASwitches);
}
}
/*
* The default value for the 'touchScreen' parameter is an empty string; machine configs must explicitly
* select one of the following values, via the 'touchscreen' attribute in the <video> element, to enable any
* touch-screen support.
*/
if (this.sTouchScreen == "mouse") {
this.mouse = cmp.getMachineComponent("Mouse");
if (this.mouse) this.captureTouch(Video.TOUCH.MOUSE);
}
else if (this.sTouchScreen == "keygrid") {
if (this.kbd) this.captureTouch(Video.TOUCH.KEYGRID);
}
};
/**
* setBinding(sHTMLType, sBinding, control, sValue)
*
* @this {Video}
* @param {string|null} sHTMLType is the type of the HTML control (eg, "button", "list", "text", "submit", "textarea", "canvas")
* @param {string} sBinding is the value of the 'binding' parameter stored in the HTML control's "data-value" attribute (eg, "refresh")
* @param {Object} control is the HTML control DOM object (eg, HTMLButtonElement)
* @param {string} [sValue] optional data value
* @return {boolean} true if binding was successful, false if unrecognized binding request
*/
Video.prototype.setBinding = function(sHTMLType, sBinding, control, sValue)
{
var video = this;
if (!this.bindings[sBinding]) {
/*
* We now save every binding that comes in, so that if there are bindings for "caps-lock' and the like,
* we can forward them to the Keyboard.
*/
this.bindings[sBinding] = control;
switch (sBinding) {
case "fullScreen":
if (this.container && this.container.doFullScreen) {
control.onclick = function onClickFullScreen() {
if (DEBUG) video.printMessage("fullScreen()");
video.doFullScreen();
};
} else {
if (DEBUG) this.log("FullScreen API not available");
control.parentNode.removeChild(/** @type {Node} */ (control));
}
return true;
case "lockPointer":
this.sLockMessage = control.textContent;
if (this.inputScreen && this.inputScreen.lockPointer) {
control.onclick = function onClickLockPointer() {
if (DEBUG) video.printMessage("lockPointer()");
video.lockPointer(true);
};
} else {
if (DEBUG) this.log("Pointer Lock API not available");
control.parentNode.removeChild(/** @type {Node} */ (control));
}
return true;
case "refresh":
control.onclick = function onClickRefresh() {
if (DEBUG) video.printMessage("refreshScreen()");
video.updateScreen(true);
};
return true;
default:
break;
}
}
return false;
};
/**
* setFocus()
*
* @this {Video}
*/
Video.prototype.setFocus = function()
{
if (this.inputScreen) this.inputScreen.focus();
};
/**
* getInput()
*
* This is an interface used by the Mouse component, so that it can invoke capture/release mouse events from the screen element.
*
* @this {Video}
* @param {Mouse} [mouse]
* @return {Object|undefined}
*/
Video.prototype.getInput = function(mouse)
{
this.mouse = mouse;
return this.inputScreen;
};
/**
* doFullScreen()
*
* @this {Video}
* @return {boolean} true if request successful, false if not (eg, failed OR not supported)
*/
Video.prototype.doFullScreen = function()
{
var fSuccess = false;
if (this.container) {
if (this.container.doFullScreen) {
/*
* Styling the container with a width of "100%" and a height of "auto" works great when the aspect ratio
* of our virtual screen is at least roughly equivalent to the physical screen's aspect ratio, but now that
* we support virtual VGA screens with an aspect ratio of 1.33, that's very much out of step with modern
* wide-screen monitors, which usually have an aspect ratio of 1.6 or greater.
*
* And unfortunately, none of the browsers I've tested appear to make any attempt to scale our container to
* the physical screen's dimensions, so the bottom of our screen gets clipped. To prevent that, I reduce
* the width from 100% to whatever percentage will accommodate the entire height of the virtual screen.
*
* NOTE: Mozilla recommends both a width and a height of "100%", but all my tests suggest that using "auto"
* for height works equally well, so I'm sticking with it, because "auto" is also consistent with how I've
* implemented a responsive canvas when the browser window is being resized.
*/
var sWidth = "100%";
var sHeight = "auto";
if (screen && screen.width && screen.height) {
var aspectPhys = screen.width / screen.height;
var aspectVirt = this.cxScreen / this.cyScreen;
if (aspectPhys > aspectVirt) {
sWidth = Math.round(aspectVirt / aspectPhys * 100) + '%';
}
// TODO: We may need to someday consider the case of a physical screen with an aspect ratio < 1.0....
}
if (!this.fGecko) {
this.container.style.width = sWidth;
this.container.style.height = sHeight;
} else {
/*
* Sadly, the above code doesn't work for Firefox, because as http://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Using_full_screen_mode
* explains:
*
* 'It's worth noting a key difference here between the Gecko and WebKit implementations at this time:
* Gecko automatically adds CSS rules to the element to stretch it to fill the screen: "width: 100%; height: 100%".
*
* Which would be OK if Gecko did that BEFORE we're called, but apparently it does that AFTER, effectively
* overwriting our careful calculations. So we style the inner element (canvasScreen) instead, which
* requires even more work to ensure that the canvas is properly centered. FYI, this solution is consistent
* with Mozilla's recommendation for working around their automatic CSS rules:
*
* '[I]f you're trying to emulate WebKit's behavior on Gecko, you need to place the element you want
* to present inside another element, which you'll make fullscreen instead, and use CSS rules to adjust
* the inner element to match the appearance you want.'
*/
this.canvasScreen.style.width = sWidth;
this.canvasScreen.style.width = sWidth;
this.canvasScreen.style.display = "block";
this.canvasScreen.style.margin = "auto";
}
this.container.style.backgroundColor = "black";
this.container.doFullScreen();
fSuccess = true;
}
this.setFocus();
}
return fSuccess;
};
/**
* notifyFullScreen(fFullScreen)
*
* @this {Video}
* @param {boolean|null} fFullScreen (null if there was a full-screen error)
*/
Video.prototype.notifyFullScreen = function(fFullScreen)
{
if (!fFullScreen && this.container) {
if (!this.fGecko) {
this.container.style.width = this.container.style.height = "";
} else {
this.canvasScreen.style.width = this.canvasScreen.style.height = "";
}
}
this.printMessage("notifyFullScreen(" + fFullScreen + ")", true);
if (this.kbd) this.kbd.notifyEscape(fFullScreen);
};
/**
* lockPointer()
*
* @this {Video}
* @param {boolean} fLock
* @return {boolean} true if request successful, false if not (eg, failed OR not supported)
*/
Video.prototype.lockPointer = function(fLock)
{
var fSuccess = false;
if (this.inputScreen) {
if (fLock) {
if (this.inputScreen.lockPointer) {
this.inputScreen.lockPointer();
if (this.mouse) this.mouse.notifyPointerLocked(true);
fSuccess = true;
}
} else {
if (this.inputScreen.unlockPointer) {
this.inputScreen.unlockPointer();
if (this.mouse) this.mouse.notifyPointerLocked(false);
fSuccess = true;
}
}
this.setFocus();
}
return fSuccess;
};
/**
* notifyPointerActive(fActive)
*
* @this {Video}
* @param {boolean} fActive
* @return {boolean} true if autolock enabled AND pointer lock supported, false if not
*/
Video.prototype.notifyPointerActive = function(fActive)
{
if (this.fAutoLock) {
return this.lockPointer(fActive);
}
return false;
};
/**
* notifyPointerLocked(fLocked)
*
* @this {Video}
* @param {boolean} fLocked
*/
Video.prototype.notifyPointerLocked = function(fLocked)
{
if (this.mouse) {
this.mouse.notifyPointerLocked(fLocked);
if (this.kbd) this.kbd.notifyEscape(fLocked);
}
var control = this.bindings["lockPointer"];
if (control) control.textContent = (fLocked? "Press Esc to Unlock Pointer" : this.sLockMessage);
};
/**
* captureTouch(nTouchConfig)
*
* @this {Video}
* @param {number} nTouchConfig (must be one of the supported Video.TOUCH values)
*/
Video.prototype.captureTouch = function(nTouchConfig)
{
var control = this.inputScreen;
if (control) {
var video = this;
if (!this.nTouchConfig) {
control.addEventListener(
'touchstart',
function onTouchStart(event) { video.onTouchStart(event); },
false // we'll specify false for the 'useCapture' parameter for now...
);
control.addEventListener(
'touchmove',
function onTouchMove(event) { video.onTouchMove(event); },
true
);
control.addEventListener(
'touchend',
function onTouchEnd(event) { video.onTouchEnd(event); },
false // we'll specify false for the 'useCapture' parameter for now...
);
/*
* Using desktop mouse events to simulate touch events should only be enabled as needed.
*
if (DEBUG) {
control.addEventListener(
'mousedown',
function onMouseDown(event) { video.onTouchStart(event); },
false // we'll specify false for the 'useCapture' parameter for now...
);
control.addEventListener(
'mousemove',
function onMouseMove(event) { video.onTouchMove(event); },
true
);
control.addEventListener(
'mouseup',
function onMouseUp(event) { video.onTouchEnd(event); },
false // we'll specify false for the 'useCapture' parameter for now...
);
}
*/
// this.log("touch events captured");
this.nTouchConfig = nTouchConfig;
this.xTouch = this.yTouch = this.timeTouch = -1;
/*
* As long as fTouchDefault is false, we call preventDefault() on every touch event, to prevent
* the page from moving/scrolling while the canvas is processing touch events. However, there must
* also be exceptions to permit the soft keyboard to activate; see processTouchEvent() for details.
*/
this.fTouchDefault = false;
/*
* I also need to come up with some rules for when the simulated mouse's primary button stays down.
* Let's try setting a timeout handler whenever a touchstart is received, which we'll immediately cancel
* as soon as a touchmove or touchend event is received, and if the timeout handler fires, we'll set
* fLongTouch to true.
*/
this.hLongTouch = null;
this.fLongTouch = false;
this.onLongTouch = function onLongTouch() { video.startLongTouch(); };
}
}
};
/**
* onFocusChange(fFocus)
*
* @this {Video}
* @param {boolean} fFocus is true if gaining focus, false if losing it
*/
Video.prototype.onFocusChange = function(fFocus)
{
/*
* As per http://stackoverflow.com/questions/6740253/disable-scrolling-when-changing-focus-form-elements-ipad-web-app,
* I decided to try this work-around to prevent the webpage from scrolling around whenever the canvas is given
* focus. That sort of scrolling-into-view sounds great in principle, but in practice, if you were reading some other
* portion of the page, it can be irritating to be scrolled away from that portion when refreshing/returning to the page.
*
* However, this work-around doesn't seem to work with the latest version of Safari (or else I misunderstood something).
*
* if (fFocus) {
* window.scrollTo(0, 0);
* document.body.scrollTop = 0;
* }
*/
this.fHasFocus = fFocus;
if (this.kbd) this.kbd.onFocusChange(fFocus);
};
/*
Video.prototype.releaseTouch = function()
{
};
*/
/**
* onTouchStart(event)
*
* @this {Video}
* @param {Event} event object from a 'touch' event
*/
Video.prototype.onTouchStart = function(event)
{
if (DEBUG) this.printMessage("onTouchStart()");
this.processTouchEvent(event, true);
};
/**
* onTouchMove(event)
*
* @this {Video}
* @param {Event} event object from a 'touch' event
*/
Video.prototype.onTouchMove = function(event)
{
if (DEBUG) this.printMessage("onTouchMove()");
this.processTouchEvent(event);
};
/**
* onTouchEnd(event)
*
* @this {Video}
* @param {Event} event object from a 'touch' event
*/
Video.prototype.onTouchEnd = function(event)
{
if (DEBUG) this.printMessage("onTouchEnd()");
this.processTouchEvent(event, false);
};
/**
* processTouchEvent(event, fStart)
*
* If nTouchConfig is non-zero, touch event handlers are installed, which pass their events to this function.
*
* What we do with those events here depends on the value of nTouchConfig. Originally, the only supported
* configuration was the experimental conversion of touch events into arrow keys, based on an invisible grid
* that divided the screen into thirds; that configuration is now identified as Video.TOUCH.KEYGRID.
*
* The new preferred configuration is Video.TOUCH.MOUSE, which does little more than allow you to "push" the
* simulated mouse around. If Video.TOUCH.MOUSE is enabled, it's already been confirmed the machine has a mouse.
*
* @this {Video}
* @param {Event} event object from a 'touch' event
* @param {boolean} [fStart] (true if 'touchstart', false if 'touchend', undefined if 'touchmove')
*/
Video.prototype.processTouchEvent = function(event, fStart)
{
var xTouch, yTouch;
// if (!event) event = window.event;
/*
* Touch coordinates (that is, the pageX and pageY properties) are relative to the page, so to make
* them relative to the canvas, we must subtract the canvas's left and top positions. This Apple web page:
*
* https://developer.apple.com/library/safari/documentation/AudioVideo/Conceptual/HTML-canvas-guide/AddingMouseandTouchControlstoCanvas/AddingMouseandTouchControlstoCanvas.html
*
* makes it sound simple, but it turns out we have to walk the canvas' entire "parentage" of DOM elements
* to get the exact offsets.
*
* TODO: Determine whether the getBoundingClientRect() code used in panel.js for mouse events can also
* be used here to simplify this annoyingly complicated code for touch events.
*/
var xTouchOffset = 0;
var yTouchOffset = 0;
var eCurrent = this.canvasScreen;
do {
if (!isNaN(eCurrent.offsetLeft)) {
xTouchOffset += eCurrent.offsetLeft;
yTouchOffset += eCurrent.offsetTop;
}
} while ((eCurrent = eCurrent.offsetParent));
/*
* Due to the responsive nature of our pages, the displayed size of the canvas may be smaller than the
* allocated size, and the coordinates we receive from touch events are based on the currently displayed size.
*/
var xScale = this.cxScreen / this.canvasScreen.offsetWidth;
var yScale = this.cyScreen / this.canvasScreen.offsetHeight;
/**
* @name Event
* @property {Array} targetTouches
*/
if (!event.targetTouches || !event.targetTouches.length) {
xTouch = event.pageX;
yTouch = event.pageY;
} else {
xTouch = event.targetTouches[0].pageX;
yTouch = event.targetTouches[0].pageY;
}
xTouch = ((xTouch - xTouchOffset) * xScale);
yTouch = ((yTouch - yTouchOffset) * yScale);
if (this.nTouchConfig == Video.TOUCH.KEYGRID) {
var xThird = (xTouch / (this.cxScreen / 3)) | 0;
var yThird = (yTouch / (this.cyScreen / 3)) | 0;
/*
* At this point, xThird and yThird should both be one of 0, 1 or 2, indicating which horizontal and vertical
* third of the virtual screen the touch event occurred.
*/
if (/* xThird == 1 && */ yThird != 1) {
if (!yThird) {
this.kbd.addActiveKey(Keyboard.CLICKCODES.UP, true);
} else {
this.kbd.addActiveKey(Keyboard.CLICKCODES.DOWN, true);
}
} else if (/* yThird == 1 && */ xThird != 1) {
if (!xThird) {
this.kbd.addActiveKey(Keyboard.CLICKCODES.LEFT, true);
} else {
this.kbd.addActiveKey(Keyboard.CLICKCODES.RIGHT, true);
}
}
} else {
if (this.mouse) {
/*
* As long as fTouchDefault is false, we call preventDefault() on every touch event, to keep
* the page stable. However, we must allow some touch event(s) to perform their default action,
* otherwise the soft keyboard can never be activated. So if a touchstart occurs at least 1/2
* second (500ms) after the last touchstart, with no intervening touchmove events, fTouchDefault
* is allowed to become true.
*/
var fTouchDefault = this.fTouchDefault;
var timeDelta = event.timeStamp - this.timeTouch;
if (fStart === true) {
this.fTouchDefault = (timeDelta > 500);
this.timeTouch = event.timeStamp;
this.hLongTouch = setTimeout(this.onLongTouch, 500);
} else {
if (this.hLongTouch != null) {
clearTimeout(this.hLongTouch);
this.hLongTouch = null;
}
}
if (fStart === undefined) {
this.fTouchDefault = false;
}
if (DEBUG) {
this.log("processTouchEvent(" + (fStart? "touchStart" : (fStart === false? "touchEnd" : "touchMove")) + "," + timeDelta + "ms," + fTouchDefault + ")");
}
if (!fTouchDefault) {
event.preventDefault();
}
if (fStart === false) {
/*
* NOTE: 200ms is merely my initial stab at a reasonable number of milliseconds to interpret a
* start/end touch sequence as a "tap"; I also make no note of any intervening move events (ie,
* events where fStart is undefined), and perhaps I should....
*/
if (this.endLongTouch()) {
return;
}
if (timeDelta < 200) {
this.mouse.clickMouse(Mouse.BUTTON.LEFT, true);
this.mouse.clickMouse(Mouse.BUTTON.LEFT, false);
return;
}
}
/*
* This 'touchmove" code mimics the 'mousemove' event processing in processMouseEvent() in mouse.js, with
* one important difference: every time touching "restarts", we need to reset the variables used to calculate
* the deltas, so that the mere act of lifting and replacing your finger doesn't generate a delta by itself.
*/
if (fStart || this.xTouch < 0 || this.yTouch < 0) {
this.xTouch = xTouch;
this.yTouch = yTouch;
}
var xDelta = Math.round(xTouch - this.xTouch);
var yDelta = Math.round(yTouch - this.yTouch);
this.xTouch = xTouch;
this.yTouch = yTouch;
// this.println("moveMouse(" + xDelta + "," + yDelta + ")");
this.mouse.moveMouse(xDelta, yDelta, this.xTouch, this.yTouch);
}
}
};
/**
* startLongTouch()
*
* @this {Video}
*/
Video.prototype.startLongTouch = function()
{
this.fLongTouch = true;
this.mouse.clickMouse(Mouse.BUTTON.LEFT, true);
};
/**
* endLongTouch()
*
* @this {Video}
* @return {boolean} true if long touch was active, false if not
*/
Video.prototype.endLongTouch = function()
{
if (this.fLongTouch) {
this.mouse.clickMouse(Mouse.BUTTON.LEFT, false);
this.fLongTouch = false;
return true;
}
return false;
};
/**
* powerUp(data, fRepower)
*
* @this {Video}
* @param {Object|null} data
* @param {boolean} [fRepower]
* @return {boolean} true if successful, false if failure
*/
Video.prototype.powerUp = function(data, fRepower)
{
if (!fRepower) {
if (!data || !this.restore) {
this.reset();
} else {
if (!this.restore(data)) return false;
}
}
return true;
};
/**
* powerDown(fSave, fShutdown)
*
* This is where we might add some method of blanking the display, without the disturbing the video
* buffer contents, and blocking all further updates to the display.
*
* @this {Video}
* @param {boolean} [fSave]
* @param {boolean} [fShutdown]
* @return {Object|boolean} component state if fSave; otherwise, true if successful, false if failure
*/
Video.prototype.powerDown = function(fSave, fShutdown)
{
return fSave? this.save() : true;
};
/**
* reset()
*
* @this {Video}
*/
Video.prototype.reset = function()
{
var fRandomize = true;
var nMonitorType = ChipSet.MONITOR.NONE;
/*
* We'll ask the ChipSet what SW1 indicates for monitor type, but we may override it if a specific
* video card model is set. For EGA, SW1 is supposed to be set to indicate NO monitor, and we rely
* on the EGA's own switch settings instead.
*/
if (this.chipset) {
nMonitorType = this.chipset.getDIPVideoMonitor();
}
/*
* As we noted in the constructor, when a model is specified, that takes precedence over any monitor
* switch settings. Conversely, when no model is specified, the nCard setting is considered provisional,
* so the monitor switch settings, if any, are allowed to determine the card type.
*/
if (!this.model) {
this.nCard = (nMonitorType == ChipSet.MONITOR.MONO? Video.CARD.MDA : Video.CARD.CGA);
}
this.nModeDefault = Video.MODE.CGA_80X25;
switch (this.nCard) {
case Video.CARD.VGA:
nMonitorType = ChipSet.MONITOR.VGACOLOR;
break;
case Video.CARD.EGA:
var aMonitors = Video.aEGAMonitorSwitches[this.bEGASwitches];
/*
* TODO: Figure out how to deal with aMonitors[2], the boolean which indicates
* whether the EGA is driving the primary monitor (true) or the secondary monitor (false).
*/
if (aMonitors) nMonitorType = aMonitors[0];
if (!nMonitorType) nMonitorType = ChipSet.MONITOR.EGACOLOR;
break;
case Video.CARD.MDA:
nMonitorType = ChipSet.MONITOR.MONO;
this.nModeDefault = Video.MODE.MDA_80X25;
break;
case Video.CARD.CGA:
/* falls through */
default:
nMonitorType = ChipSet.MONITOR.COLOR;
break;
}
if (this.nMonitorType !== nMonitorType) {
this.nMonitorType = nMonitorType;
fRandomize = true;
}
this.cardActive = null;
this.cardMono = this.cardMDA = new Card(this, Video.CARD.MDA);
this.cardColor = this.cardCGA = new Card(this, Video.CARD.CGA);
if (this.nCard < Video.CARD.EGA) {
this.cardEGA = new Card(); // define a dummy (uninitialized) EGA card for now
}
else {
this.cardEGA = new Card(this, this.nCard, null, this.cbMemory);
this.enableEGA();
}
/*
* We need to call buildFonts() *after* the card(s) are initialized but *before* setMode() is called.
*/
this.buildFonts();
this.nMode = null;
this.iCellCursor = -1; // initially, there is no visible cursor cell
this.cBlinks = -1; // initially, blinking is not active
this.cBlinkVisible = 0; // no visible blinking characters (yet)
this.setMode(this.nModeDefault);
if (this.cardActive.addrBuffer && fRandomize) {
/*
* On the initial power-on, we initialize the video buffer to random characters, as a way of testing
* whether our font(s) were successfully loaded. It's assumed that our default display mode is a text mode,
* and that since this is a reset, the CRTC.START_ADDR registers are zero as well.
*
* If this is an MDA device, then the buffer should reside at 0xB0000 through 0xB0FFF, for a total length
* of 4Kb (0x1000), where every even byte contains a character code, and every odd byte contains an attribute
* code. See the ATTR bit definitions above for applicable color, intensity, and blink values. On a CGA
* device, the buffer resides at 0xB8000 through 0xBBFFF, for a total length of 16Kb.
*
* Note that the only valid MDA display mode (7) is the 80x25 text mode, which uses 4000 bytes (2000 character
* bytes + 2000 attribute bytes), not all 4096 bytes; addrScreenLimit reflects the visible limit, not the
* physical limit. Also, as noted in updateScreen(), this simplistic calculation of the extent of visible
* screen memory is valid only for text modes; in general, it's safer to use cardActive.sizeBuffer as the extent.
*/
var addrScreenLimit = this.cardActive.addrBuffer + this.cbScreen;
for (var addrScreen = this.cardActive.addrBuffer; addrScreen < addrScreenLimit; addrScreen += 2) {
var dataRandom = (Math.random() * 0x10000)|0;
var bChar, bAttr;
if (this.nMonitorType == ChipSet.MONITOR.EGACOLOR || this.nMonitorType == ChipSet.MONITOR.VGACOLOR) {
/*
* For the EGA, we choose sequential characters; for random characters, copy the MDA/CGA code below.
*/
bChar = (addrScreen >> 1) & 0xff;
bAttr = (dataRandom >> 8) & ~Video.ATTRS.BGND_BLINK; // TODO: turn blink attributes off unless we can ensure blinking is initially disabled
if ((bAttr >> 4) == (bAttr & 0xf)) {
bAttr ^= 0x0f; // if background matches foreground, invert foreground to ensure character visibility
}
} else {
bChar = dataRandom & 0xff;
bAttr = ((dataRandom & 0x100)? (Video.ATTRS.FGND_WHITE | Video.ATTRS.BGND_BLACK) : (Video.ATTRS.FGND_BLACK | Video.ATTRS.BGND_WHITE)) | ((Video.ATTRS.FGND_BRIGHT /* | Video.ATTRS.BGND_BLINK */) & (dataRandom >> 8));
}
this.bus.setShortDirect(addrScreen, bChar | (bAttr << 8));
}
this.updateScreen(true);
}
};
/**
* enableEGA()
*
* Redirect cardMono or cardColor to cardEGA as appropriate.
*
* @this {Video}
*/
Video.prototype.enableEGA = function()
{
if (!(this.cardEGA.regMisc & Card.MISC.IO_SELECT)) {
this.cardMono = this.cardEGA;
this.cardColor = this.cardCGA; // this is done mainly to siphon away any CGA I/O
} else {
this.cardMono = this.cardMDA; // similarly, this is done to siphon away any MDA I/O
this.cardColor = this.cardEGA;
}
};
/**
* save()
*
* This implements save support for the Video component.
*
* @this {Video}
* @return {Object}
*/
Video.prototype.save = function()
{
var state = new State(this);
state.set(0, this.cardMDA.saveCard());
state.set(1, this.cardCGA.saveCard());
state.set(2, [this.nMonitorType, this.nModeDefault, this.nMode]);
state.set(3, this.cardEGA.saveCard());
return state.data();
};
/**
* restore(data)
*
* This implements restore support for the Video component.
*
* @this {Video}
* @param {Object} data
* @return {boolean} true if successful, false if failure
*/
Video.prototype.restore = function(data)
{
var a = data[2];
this.nMonitorType = a[0];
this.nModeDefault = a[1];
this.nMode = a[2];
this.cardActive = null;
this.cardMono = this.cardMDA = new Card(this, Video.CARD.MDA, data[0]);
this.cardColor = this.cardCGA = new Card(this, Video.CARD.CGA, data[1]);
/*
* If no EGA was originally initialized, then cardEGA will remain uninitialized.
*/
this.cardEGA = new Card(this, this.nCard, data[3], this.cbMemory);
if (this.cardEGA.fActive) this.enableEGA();
/*
* We need to call buildFonts() *after* the card(s) are initialized but *before* setMode() is called.
*/
this.buildFonts();
/*
* While I could restore the active card here, it's better for setMode() to do it, because
* setMode() will also take care of mapping the appropriate video buffer. So, after restore() has
* finished, we call checkMode(), because the current video mode (nMode) is determined by the
* active card state.
*
* Unfortunately, that creates a chicken-and-egg problem, since I just said I didn't want to select
* the active card here.
*
* So, we'll add some "cop-out" code to checkMode(): if there's no active card, then fall-back
* to the last known video mode (nMode) and force a call to setMode().
*
* this.cardActive = (this.cardMDA.fActive? this.cardMDA : (this.cardCGA.fActive? this.cardCGA : undefined));
*/
if (!this.checkMode()) return false;
this.checkCursor();
return true;
};
/**
* doneLoad(sURL, sFontData, nErrorCode)
*
* @this {Video}
* @param {string} sURL
* @param {string} sFontData
* @param {number} nErrorCode (response from server if anything other than 200)
*/
Video.prototype.doneLoad = function(sURL, sFontData, nErrorCode)
{
if (nErrorCode) {
this.notice("Unable to load font ROM (error " + nErrorCode + ": " + sURL + ")");
return;
}
Component.addMachineResource(this.idMachine, sURL, sFontData);
try {
/*
* The most likely source of any exception will be right here, where we're parsing the JSON-encoded data.
*/
var abFontData = eval("(" + sFontData + ")");
var ab = abFontData['bytes'] || abFontData;
if (!ab.length) {
Component.error("Empty font ROM: " + sURL);
return;
}
else if (ab.length == 1) {
Component.error(ab[0]);
return;
}
/*
* Translate the character data into separate "fonts", each of which will be a separate canvas object, with all
* 256 characters arranged in a 16x16 grid.
*/
if (ab.length == 8192) {
/*
* The assumption here is that we're dealing with the original (IBM) MDA/CGA font data, which apparently
* was identical on both MDA and CGA cards (even though the former had no use for the latter, and vice versa).
*
* First, let's take a look at the MDA portion of the data. Here are the first few rows of MDA font data,
* at the 0K and 2K boundaries:
*
* 00000000 00 00 00 00 00 00 00 00 00 00 7e 81 a5 81 81 bd |..........~.....|
* 00000010 00 00 7e ff db ff ff c3 00 00 00 36 7f 7f 7f 7f |..~........6....|
* ...
* 00000800 00 00 00 00 00 00 00 00 99 81 7e 00 00 00 00 00 |..........~.....|
* 00000810 e7 ff 7e 00 00 00 00 00 3e 1c 08 00 00 00 00 00 |..~.....>.......|
*
* 8 bytes of data from a row in each of the 2K chunks are combined to form a 8-bit wide character with
* a maximum height of 16 bits. Assembling the bits for character 0x01 (a happy face), we observe the following:
*
* 0 0 0 0 0 0 0 0 <== 00 from offset 0x0008
* 0 0 0 0 0 0 0 0 <== 00 from offset 0x0009
* 0 1 1 1 1 1 1 0 <== 7e from offset 0x000A
* 1 0 0 0 0 0 0 1 <== 81 from offset 0x000B
* 1 0 1 0 0 1 0 1 <== a5 from offset 0x000C
* 1 0 0 0 0 0 0 1 <== 81 from offset 0x000D
* 1 0 0 0 0 0 0 1 <== 81 from offset 0x000E
* 1 0 1 1 1 1 0 1 <== bd from offset 0x000F
* 1 0 0 1 1 0 0 1 <== 99 from offset 0x0808
* 1 0 0 0 0 0 0 1 <== 81 from offset 0x0809
* 0 1 1 1 1 1 1 0 <== 7e from offset 0x080A
* 0 0 0 0 0 0 0 0 <== 00 from offset 0x080B
* 0 0 0 0 0 0 0 0 <== 00 from offset 0x080C
* 0 0 0 0 0 0 0 0 <== 00 from offset 0x080D
* 0 0 0 0 0 0 0 0 <== 00 from offset 0x080E
* 0 0 0 0 0 0 0 0 <== 00 from offset 0x080F
*
* In the second 2K chunk, we observe that the last two bytes of every font cell definition are zero;
* this confirms our understanding that MDA font cell size is 8x14.
*
* Finally, there's the issue of screen cell size, which is actually 9x14 on the MDA. We compensate for that
* by building a 9x14 font, even though there's only 8x14 bits of data. As http://www.seasip.info/VintagePC/mda.html
* explains:
*
* "For characters C0h-DFh, the ninth pixel column is a duplicate of the eighth; for others, it's blank."
*
* This last point is confirmed by "The IBM Personal Computer From The Inside Out", p.295:
*
* "Another unique feature of the monochrome adapter is a set of line-drawing and area-fill characters
* that give continuous lines and filled areas. This is unusual for a display with a 9x14 character box
* because the character generator provides a row only eight dots wide. On most displays, a blank 9th
* dot is then inserted between characters. On the monochrome display, there is circuitry that duplicates
* the 8th dot into the 9th dot position for characters whose ASCII codes are 0xB0 [sic] through 0xDF."
*
* However, the above text is mistaken about the start of the range. While there ARE line-drawing characters
* in the range 0xB0-0xBF, none of them extend all the way to the right edge; IBM carefully segregated them.
* And in fact, characters 0xB0-0xB2 contain hash patterns that you would NOT want extended into the 9th column.
*
* The CGA font is part of the same ROM. In fact, there are TWO CGA fonts in the ROM: a thin 5x7 "single dot"
* font located at offset 0x1000, and a thick 7x7 "double dot" font at offset 0x1800. The latter is the default
* font, unless overridden by a jumper setting on the CGA card, so it is our default CGA font as well (although
* someday we may provide a virtual jumper setting that allows you to select the thinner font).
*
* The first offset we must pass to setFontData() is the offset of the CGA font; we choose the thicker "double dot"
* CGA font at 0x1800 (which was the PC's default font as well), instead of the thinner "single dot" font at 0x1000.
* The second offset is for the MDA font.
*/
this.setFontData(ab, [0x1800, 0x0000]);
}
else if (ab.length == 2048) {
/*
* The assumption here is that we're dealing strictly with CGA (8x8) font data, like the font data found
* in the Columbia Data Products (CDP) Font ROM.
*/
this.setFontData(ab, [0x0000]);
}
else {
this.notice("Unrecognized font data length (" + ab.length + ")");
return;
}
} catch (e) {
this.notice("Font ROM data error: " + e.message);
return;
}
/*
* If we're still here, then we're ready!
*
* UPDATE: Per issue #21, I'm issuing setReady() *only* if a valid contextScreen exists *or* a Debugger is attached.
*
* TODO: Consider a more general-purpose solution for deciding whether or not the user wants to run in a "headless" mode.
*/
if (this.contextScreen || this.dbg) this.setReady();
};
/**
* onROMLoad(abRom, aParms)
*
* Called by the ROM's copyROM() function whenever a ROM component with a 'notify' attribute containing
* our component ID has been loaded.
*
* @this {Video}
* @param {Array.<number>} abROM
* @param {Array.<number>} [aParms]
*/
Video.prototype.onROMLoad = function(abROM, aParms)
{
if (this.nCard == Video.CARD.EGA) {
/*
* TODO: Unlike the MDA/CGA font data, we may want to hang onto this data, so that we can
* regenerate the color font(s) whenever the foreground and/or background colors have changed.
*/
if (DEBUG) this.printMessage("onROMLoad(): EGA fonts loaded");
/*
* For EGA cards, in the absence of any parameters, we assume that we're receiving the original
* IBM EGA ROM, which stores its 8x14 font data at 0x2230 as one continuous sequence; the total size
* of the 8x14 font is 0xE00 bytes.
*
* At 0x3030, there is an "ALPHA SUPPLEMENT" table, which contains 15 bytes per row instead of 14,
* because each row is preceded by one byte containing the corresponding ASCII code; there are 20
* entries in the supplemental table, for a total size of 0x12C bytes.
*
* Finally, at 0x3160, we have the 8x8 font data (also known as the thicker "double dot" CGA font);
* the total size of the 8x8 font is 0x800 bytes. No other font data is present in the EGA ROM;
* the thin 5x7 "single dot" CGA font is notably absent, which is fine, because we never loaded it for
* the MDA/CGA either.
*
* TODO: Determine how the supplemental table is used and whether we need to add some "run-time"
* font generation to support it (as opposed to "init-time" generation, which is all we do now).
* There's probably a similar need for user-defined fonts; for now, they're simply not supported.
*/
this.setFontData(abROM, aParms || [0x3160, 0x2230], 8);
}
else if (this.nCard == Video.CARD.VGA) {
if (DEBUG) this.printMessage("onROMLoad(): VGA fonts loaded");
/*
* For VGA cards, in the absence of any parameters, we assume that we're receiving the original
* IBM VGA ROM, which contains an 8x14 font at 0x3F8D (and corresponding supplemental table at 0x4D8D)
* and an 8x8 font at 0x378D; however, it also contains an 8x16 font at 0x4EBA (and corresponding
* supplemental table at 0x5EBA). See our reconstructed source code in ibm-vga.nasm.
*/
this.setFontData(abROM, aParms || [0x378d, 0x3f8d], 8);
}
this.setReady();
};
/**
* getCardColors(nBitsPerPixel)
*
* @this {Video}
* @param {number} [nBitsPerPixel]
* @returns {Array}
*/
Video.prototype.getCardColors = function(nBitsPerPixel)
{
if (nBitsPerPixel == 1) {
/*
* Only 2 total colors.
*/
this.aRGB[0] = Video.aCGAColors[Video.ATTRS.FGND_BLACK];
this.aRGB[1] = Video.aCGAColors[Video.ATTRS.FGND_WHITE];
return this.aRGB;
}
if (nBitsPerPixel == 2) {
/*
* Of the 4 colors returned, the first color comes from regColor and the other 3 come from one of
* the two hard-coded CGA color sets:
*
* Color Set 1 Color Set 2
* ----------- -----------
* Background (0x00) Background (0x00)
* Green (0x12) Cyan (0x13)
* Red (0x14) Magenta (0x15)
* Brown (0x16) White (0x17)
*
* The numbers in parentheses are the EGA ATC palette register values that the EGA BIOS uses for each
* color set; on an EGA, I synthesize a fake CGA regColor value, until I (TODO:) figure out exactly how
* the EGA simulates the CGA color palette.
*/
var regColor = this.cardActive.regColor;
if (this.cardActive === this.cardEGA) {
var bBackground = this.cardEGA.regATCData[0];
regColor = bBackground & Card.CGA.COLOR.BORDER;
if (bBackground & Card.ATC.PALETTE.BRIGHT) regColor |= Card.CGA.COLOR.BRIGHT;
if (this.cardEGA.regATCData[1] != 0x12) regColor |= Card.CGA.COLOR.COLORSET2;
}
this.aRGB[0] = Video.aCGAColors[regColor & (Card.CGA.COLOR.BORDER | Card.CGA.COLOR.BRIGHT)];
var aColorSet = (regColor & Card.CGA.COLOR.COLORSET2)? Video.aCGAColorSet2 : Video.aCGAColorSet1;
for (var iColor = 0; iColor < aColorSet.length; iColor++) {
this.aRGB[iColor+1] = Video.aCGAColors[aColorSet[iColor]];
}
return this.aRGB;
}
if (this.cardColor === this.cardCGA) {
/*
* There's no need to update this.aRGB if we simply want to return a hard-coded set of 16 colors.
*/
return Video.aCGAColors;
}
this.assert(this.cardColor === this.cardEGA);
if (this.fRGBValid && nBitsPerPixel && !this.aRGB[16]) {
this.fRGBValid = false;
}
if (!this.fRGBValid) {
var card = this.cardEGA;
var aDAC = card.regDACData;
var aRegs, i, dw, b, bRed, bGreen, bBlue;
if (nBitsPerPixel == 8) {
/*
* The card must be a VGA, and it's using an (8bpp) mode that bypasses the ATC, so we need to pull
* RGB data exclusively from the 256-entry DAC; each entry contains 6-bit red, green, and blue values
* packed into bits 0-5, 6-11, and 12-17, respectively, each of which we effectively shift left 2 bits:
* a crude 6-to-8-bit color conversion.
*/
for (i = 0; i < 256; i++) {
dw = aDAC[i] || 0;
this.assert(dw >= 0 && dw <= 0x3ffff);
bRed = (dw << 2) & 0xfc;
bGreen = (dw >> 4) & 0xfc;
bBlue = (dw >> 10) & 0xfc;
this.aRGB[i] = [bRed, bGreen, bBlue, 0xff];
}
} else {
/*
* We need to pull RGB data from the ATC; moreover, if the ATC hasn't been initialized yet,
* we go with a default EGA-compatible 16-color palette. We'll also use the DAC if there is one
* (ie, this is actually a VGA) and it appears to be initialized (ie, the VGA BIOS has been run).
*/
var fDAC = (aDAC && aDAC[255]);
aRegs = (card.regATCData[15] != null? card.regATCData : Video.aEGAPalDef);
for (i = 0; i < 16; i++) {
b = aRegs[i] & Card.ATC.PALETTE.MASK;
/*
* If the DAC is valid, we need to supplement the 6 bits of each ATC palette entry with the values
* for bits 6 and 7 from the ATC COLORSEL register (and overwrite bits 4 and 5 if ATC.MODE.COLORSEL_ALL
* is set as well).
*
* The only reasons the DAC wouldn't be valid are if 1) we're trying to display an image before the machine
* and its BIOS have had a chance to initialize the DAC (because we don't preset it to anything, although
* perhaps we should), or 2) this is an EGA, which doesn't have a DAC.
*/
if (fDAC) {
b |= (card.regATCData[Card.ATC.COLORSEL.INDX] & (Card.ATC.COLORSEL.DAC_BIT7 | Card.ATC.COLORSEL.DAC_BIT6)) << 4;
if (card.regATCData[Card.ATC.MODE.INDX] & Card.ATC.MODE.COLORSEL_ALL) {
b &= ~0x30;
b |= (card.regATCData[Card.ATC.COLORSEL.INDX] & (Card.ATC.COLORSEL.DAC_BIT5 | Card.ATC.COLORSEL.DAC_BIT4)) << 4;
}
this.assert(b >= 0 && b <= 255);
dw = aDAC[b];
this.assert(dw >= 0 && dw <= 0x3ffff);
bRed = (dw << 2) & 0xfc;
bGreen = (dw >> 4) & 0xfc;
bBlue = (dw >> 10) & 0xfc;
} else {
bRed = (((b & 0x04)? 0xaa : 0) | ((b & 0x20)? 0x55 : 0));
bGreen = (((b & 0x02)? 0xaa : 0) | ((b & 0x10)? 0x55 : 0));
bBlue = (((b & 0x01)? 0xaa : 0) | ((b & 0x08)? 0x55 : 0));
}
this.aRGB[i] = [bRed, bGreen, bBlue, 0xff];
}
}
this.fRGBValid = true;
}
return this.aRGB;
};
/**
* setFontData(abFontData, aFontOffsets, cxFontChar)
*
* To support partial font rebuilds (required for the EGA), we now preserve the original font data (abFontData),
* font offsets (aFontOffsets), and font character width (8 for the EGA, undefined for the MDA/CGA).
*
* TODO: Ultimately, we want to have exactly one dedicated font for the EGA, the data for which we'll read directly
* from plane 2 of video memory, instead of relying on the original font data in ROM. Relying on the ROM data was
* originally just a crutch to help get EGA support bootstrapped.
*
* Also, for the MDA/CGA, we should be discarding the font data after the first buildFonts() call, because we
* should not need to ever rebuild the fonts for those cards (both their font patterns and colors were hard-coded).
*
* @this {Video}
* @param {*} abFontData is the raw font data, from the ROM font file
* @param {Array.<number>} aFontOffsets contains offsets into abFontData: [0] for CGA, [1] for MDA
* @param {number} [cxFontChar] is a fixed character width to use for all fonts; undefined to use MDA/CGA defaults
*/
Video.prototype.setFontData = function(abFontData, aFontOffsets, cxFontChar)
{
this.abFontData = abFontData;
this.aFontOffsets = aFontOffsets;
this.cxFontChar = cxFontChar;
};
/**
* buildFonts()
*
* buildFonts() is called whenever the Video component is reset or restored; we used to build the fonts as soon
* as the ROM containing them was loaded, and then throw away the underlying font data, but with the EGA's ability
* to change the color of any font, font building must now be deferred until the reset or restore notifications,
* ensuring we have access to all the colors the card is currently programmed to use.
*
* We're also called whenever EGA palette registers are modified, since one or more fonts will likely need
* to be rebuilt (this is because our fonts contain pre-rendered images of all glyphs for all 16 active colors).
* Calls to buildFonts() should not be expensive though: the underlying createFont() function rebuilds a font only
* if its color has actually changed.
*
* TODO: Our font code is still written with the assumption that, like the MDA/CGA, the underlying font data never
* changes. The EGA, however, stores its fonts in plane 2, which means fonts are dynamic; this needs to be fixed.
*
* Supporting dynamic EGA fonts should not be hard though. We can get rid of abFontData and simply build a
* temporary snapshot of all the font bytes in plane 2 of the EGA's video buffer (adwMemory), and pass that on to
* buildFont() instead. We'll also need to either invalidate the existing font's color (to trigger a rebuild) or
* pass a new "force rebuild" flag.
*
* Once that's done, an added benefit will be that we can build just the font(s) that have been loaded into plane 2,
* instead of the multitude of fonts that we now build on a just-in-case basis (eg, the MDA font, the 8x8 CGA font
* for 43-line mode, and so on).
*
* @this {Video}
* @param {boolean} [fRebuild] (true if this is a rebuild, not an initial build)
* @return {boolean} true if any or all fonts were (re)built, false if nothing changed
*/
Video.prototype.buildFonts = function(fRebuild)
{
var fChanges = false;
/*
* There's no point building fonts if this is a non-windowed (command-line) environment
* OR no font data is available (OR this is a rebuild AND we're currently in a graphics mode).
*
* In other words, build fonts if this IS a windowed environment AND font data is available
* AND this is not a rebuild, OR it IS a rebuild but we're in a graphics mode (ie, nFont is zero).
*/
if (window && this.abFontData && (!fRebuild || this.nFont)) {
var offSplit = 0x0000;
var cxChar = this.cxFontChar? this.cxFontChar : 8;
var aRGBColors = this.getCardColors();
if (this.aFontOffsets[0] != null) {
if (this.buildFont(Video.FONT.CGA, this.aFontOffsets[0], offSplit, cxChar, 8, this.abFontData, aRGBColors)) {
fChanges = true;
}
}
offSplit = this.cxFontChar? 0 : 0x0800;
cxChar = this.cxFontChar? this.cxFontChar : 9;
if (this.aFontOffsets[1] != null) {
if (this.buildFont(Video.FONT.MDA, this.aFontOffsets[1], offSplit, cxChar, 14, this.abFontData, Video.aMDAColors, Video.aMDAColorMap)) {
fChanges = true;
}
if (this.cxFontChar) {
if (this.buildFont(this.nCard, this.aFontOffsets[1], 0, this.cxFontChar, 14, this.abFontData, aRGBColors)) {
fChanges = true;
}
}
}
}
return fChanges;
};
/**
* buildFont(nFont, offData, offSplit, cxChar, cyChar, abFontData, aRGBColors, aColorMap)
*
* This is a wrapper for createFont() which also takes care loading double-size fonts when fDoubleFont is set.
*
* @this {Video}
* @param {number} nFont
* @param {number|null} offData is the offset of the font data, null if none
* @param {number} offSplit is the offset of any split font data, or zero if not split
* @param {number} cxChar is the width of the font characters
* @param {number} cyChar is the height of the font characters
* @param {*} abFontData is the raw font data, from the ROM font file
* @param {Array} aRGBColors is an array of color RGB variations, corresponding to supported FGND attribute values
* @param {Array} [aColorMap] contains color indexes corresponding to attribute values (if not supplied, the mapping is assumed to be 1-1)
* @return {boolean} true if any or all fonts were (re)built, false if nothing changed
*/
Video.prototype.buildFont = function(nFont, offData, offSplit, cxChar, cyChar, abFontData, aRGBColors, aColorMap)
{
var fChanges = false;
if (offData != null) {
if (DEBUG && this.messageEnabled()) {
this.printMessage("buildFont(" + nFont + "): building " + Video.cardSpecs[nFont][0] + " font");
}
if (this.createFont(nFont, offData, offSplit, cxChar, cyChar, abFontData, aRGBColors, aColorMap)) fChanges = true;
/*
* If font-doubling is enabled, then load a double-size version of the font as well, as it provides
* sharper rendering, especially when the screen cell size is a multiple of the above font cell size;
* in the case of the CGA, this may also be useful for 40-column modes.
*/
if (this.fDoubleFont) {
nFont <<= 1;
if (DEBUG && this.messageEnabled()) {
this.printMessage("buildFont(" + nFont + "): building " + Video.cardSpecs[nFont >> 1][0] + " double-size font");
}
if (this.createFont(nFont, offData, offSplit, cxChar, cyChar, abFontData, aRGBColors, aColorMap)) fChanges = true;
}
}
return fChanges;
};
/**
* createFont(nFont, offData, offSplit, cxChar, cyChar, abFontData, aRGBColors, aColorMap)
*
* All color variations are stored on the same font canvas, arranged vertically as a series of grids, where each
* grid is a 16x16 character glyph array.
*
* Since every character must be drawn first with its background color and then with the foreground shape on top,
* I used to include a series of empty cells at the top every font canvas containing all supported background colors
* (ie, before the character grids). But now createFont() also creates an aCSSColors array that is saved alongside
* the font canvas, and updateChar() uses that array in conjunction with fillRect() to draw character backgrounds.
*
* @this {Video}
* @param {number} nFont
* @param {number} offData is the offset of the font data
* @param {number} offSplit is the offset of any split font data, or zero if not split
* @param {number} cxChar is the width of the font characters
* @param {number} cyChar is the height of the font characters
* @param {*} abFontData is the raw font data, from the ROM font file
* @param {Array} aRGBColors is an array of color RGB variations, corresponding to supported FGND attribute values
* @param {Array|undefined} aColorMap contains color indexes corresponding to attribute values (if not supplied, the mapping is assumed to be 1-1)
* @return {boolean} true if any or all fonts were (re)created, false if nothing changed
*/
Video.prototype.createFont = function(nFont, offData, offSplit, cxChar, cyChar, abFontData, aRGBColors, aColorMap)
{
var fChanges = false;
var nDouble = (nFont & 0x1)? 0 : 1;
var font = this.aFonts[nFont];
var nColors = (aRGBColors.length < 16? aRGBColors.length : 16);
if (!font) {
font = {
cxCell: cxChar << nDouble,
cyCell: cyChar << nDouble,
aCSSColors: new Array(nColors),
aRGBColors: aRGBColors.slice(0, nColors), // using the Array slice() method to simply make a copy
aColorMap: aColorMap,
aCanvas: new Array(nColors)
};
}
for (var iColor = 0; iColor < nColors; iColor++) {
var rgbColor = aRGBColors[iColor];
var rgbColorOrig = font.aCSSColors[iColor]? font.aRGBColors[iColor] : [];
if (rgbColor[0] !== rgbColorOrig[0] || rgbColor[1] !== rgbColorOrig[1] || rgbColor[2] !== rgbColorOrig[2]) {
if (DEBUG && this.messageEnabled()) {
this.printMessage("creating font color " + iColor + " for font " + nFont);
}
this.createFontColor(font, iColor, rgbColor, nDouble, offData, offSplit, cxChar, cyChar, abFontData);
fChanges = true;
}
}
this.aFonts[nFont] = font;
return fChanges;
};
/**
* createFontColor(font, iColor, rgbColor, nDouble, offData, offSplit, cxChar, cyChar, abFontData)
*
* @this {Video}
* @param {Object} font
* @param {number} iColor
* @param {Array} rgbColor contains the RGB values for iColor
* @param {number} nDouble is 1 to double output font dimensions, 0 to match input dimensions
* @param {number} offData is the offset of the font data
* @param {number} offSplit is the offset of any split font data, or zero if not split
* @param {number} cxChar is the width of the font characters
* @param {number} cyChar is the height of the font characters
* @param {*} abFontData is the raw font data, from the ROM font file
*/
Video.prototype.createFontColor = function(font, iColor, rgbColor, nDouble, offData, offSplit, cxChar, cyChar, abFontData)
{
/*
* Now we're ready to create a 16x16 character grid for the specified color. Note that all
* the character bits are opaque (alpha=0xff) while all the surrounding bits are transparent
* (alpha=0x00, as specified in the 4th byte of rgbOff).
*
* Originally, I created 256 ImageData objects, using context.createImageData(cxChar,cyChar),
* then setting its pixels to match those of an individual character, and then drawing characters
* with contextFont.putImageData(). But putImageData() is relatively slow....
*
* Now I create a new canvas, with dimensions that allow me to arrange all 256 characters in an
* 16x16 grid -- much like the "chargen.png" bitmap used in the C1Pjs version of the Video component.
* Then drawing becomes much the same as before, because it turns out that drawImage() accepts either
* an image object OR a canvas object.
*
* This also yields better performance, since drawImage() is much faster than putImageData().
* We still have to use putImageData() to build the font canvas, but that's a one-time operation.
*/
var rgbOff = [0x00, 0x00, 0x00, 0x00];
var canvasFont = document.createElement("canvas");
canvasFont.width = font.cxCell << 4;
canvasFont.height = (font.cyCell << 4);
var contextFont = canvasFont.getContext("2d");
/*
* See notes above regarding ImageSmoothingEnabled....
*
contextFont['mozImageSmoothingEnabled'] = false;
contextFont['webkitImageSmoothingEnabled'] = false;
*/
var iChar, x, y;
var cyLimit = (cyChar < 8 || !offSplit)? cyChar : 8;
var imageChar = contextFont.createImageData(font.cxCell, font.cyCell);
for (iChar = 0; iChar < 256; iChar++) {
for (y = 0; y < cyChar; y++) {
/*
* fUnderline should be true only in the FONT_MDA case, and only for the odd color variations
* (1 and 3, out of variations 0 to 4), and only for the two bottom-most rows of the character cell
* (which I still need to confirm)
*/
var fUnderline = (font.aColorMap && (iColor & 0x1) && y >= cyChar - 2);
var offChar = (y < cyLimit? offData + iChar * cyLimit + y : offSplit + iChar * cyLimit + y - cyLimit);
var b = abFontData[offChar];
for (var nRowDoubler = 0; nRowDoubler <= nDouble; nRowDoubler++) {
for (x = 0; x < cxChar; x++) {
/*
* This "bit" of logic takes care of those characters (0xC0-0xDF) whose 9th bit must mirror the 8th bit;
* in all other cases, any bit past the 8th bit is automatically zero. It also takes care of embedding a solid
* row of bits whenever fUnderline is true.
*
* TODO: For EGA/VGA, replication of the 9th dot needs to be based on the TEXT_9DOT bit of the ATC.MODE
* register, which is particularly important for user-defined fonts that do not want that bit replicated.
*/
var bit = (fUnderline? 1 : (b & (0x80 >> (x >= 8 && iChar >= 0xC0 && iChar <= 0xDF? 7 : x))));
var xDst = (x << nDouble);
var yDst = (y << nDouble) + nRowDoubler;
var rgb = (bit? rgbColor : rgbOff);
this.setPixel(imageChar, xDst, yDst, rgb);
if (nDouble) this.setPixel(imageChar, xDst + 1, yDst, rgb);
}
}
}
/*
* (iChar >> 4) performs the integer equivalent of Math.floor(iChar / 16), and (iChar & 0xf) is the equivalent of (iChar % 16).
*/
contextFont.putImageData(imageChar, x = (iChar & 0xf) * font.cxCell, y = (iChar >> 4) * font.cyCell);
}
/*
* The colors for cell backgrounds and cursor elements must be converted to CSS color strings.
*/
font.aCSSColors[iColor] = "#" + str.toHex(rgbColor[0], 2) + str.toHex(rgbColor[1], 2) + str.toHex(rgbColor[2], 2);
font.aRGBColors[iColor] = rgbColor;
/*
* Enable this code if you want to see what the generated font looks like....
*
if (MAXDEBUG) {
var iSrcColor = (iColor == 15? 0 : iColor + 1);
this.contextScreen.fillStyle = aCSSColors[iSrcColor];
this.contextScreen.fillRect(iColor*(font.cxCell<<2), 0, canvasFont.width>>2, font.cyCell<<4);
this.contextScreen.drawImage(canvasFont, 0, iColor*(font.cyCell<<4), canvasFont.width>>2, font.cyCell<<4, iColor*(font.cxCell<<2), 0, canvasFont.width>>2, font.cyCell<<4);
}
*/
font.aCanvas[iColor] = canvasFont;
};
/**
* checkBlink()
*
* Called at the end of every updateScreen(), which may have updated cBlinkVisible to a non-zero value.
*
* Also called at the end of every checkCursor(); ie, whenever the CRT register(s) affecting the position or shape
* of the hardware cursor have been modified, and any of iCellCursor, yCursor or cyCursor have been modified as a result.
*
* Note that the cursor always blinks when it's ON; it can only be turned OFF, moved off-screen, or its rate set to half
* the normal blink rate (by default, it blinks at the normal blink rate). Bits 5-6 of the CRTC.CURSOR_START register can
* be set as follows:
*
* 00: Cursor blinks at normal blink rate
* 01: Cursor is off
* 10: (Same as 00)
* 11: Cursor blinks at half the normal blink rate
*
* According to documentation, the normal blink rate is 1/16 of the frame rate (8 frames on, 8 off).
*
* TODO: As an aside, I've observed in the "real world" that the MDA cursor cycles about 3 times per second, and by "cycle"
* I mean one full off-and-on-again cycle. I'm assuming that's the normal rate (00), not the slower "half rate" (11).
* Since that's faster than our current cursor blink rate, we should look into an option to boost our rate, without adversely
* affecting the attribute blink rate (which is currently hard-coded at half the cursor blink rate), and we should look into
* supporting "half rate" blinking, too.
*
* @this {Video}
* @return {boolean} true if there are things to blink, false if not
*/
Video.prototype.checkBlink = function()
{
if (this.cBlinkVisible > 0 || this.iCellCursor >= 0) {
if (this.cBlinks < 0) {
this.cBlinks = 0;
/*
* At this point, we can either fire up our own timer (doBlink), or rely on updateScreen()
* being called by the CPU at regular bursts (eg, CPU.VIDEO_UPDATES_PER_SECOND = 60) and advance
* cBlinks at the start of updateScreen() accordingly.
*
* doBlink() wants to increment cBlinks every 266ms. On the other hand, if updateScreen() is being
* called 60 times per second, that's about once every 16ms, so if every 16th updateScreen() increments
* cBlinks, cBlinks should advance at the same rate.
*
* The only downside to relying on the CPU driving our blink count is that whenever the CPU is halted
* (eg, by the PCjs debugger) all blinking stops -- all characters with the blink attribute AND the cursor.
*
* But we can simply say that when we halt, we mean "halt everything" (ie, call it a feature).
*
* this.doBlink(true);
*/
}
return true;
}
this.cBlinks = -1;
return false;
};
/**
* checkCursor()
*
* Called whenever a CRT data register is updated, since there are multiple registers that can affect the
* visibility of the cursor (more than these, actually, but I'm going to limit my initial support to standard
* ROM BIOS controller settings):
*
* CRTC.MAX_SCAN
* CRTC.CURSOR_START
* CRTC.CURSOR_END
* CRTC.START_ADDR_HI
* CRTC.START_ADDR_LO
* CRTC.CURSOR_ADDR_HI
* CRTC.CURSOR_ADDR_LO
*
* @this {Video}
* @return {boolean} true if the cursor is visible, false if not
*/
Video.prototype.checkCursor = function()
{
/*
* The "hardware cursor" is never visible in graphics modes.
*/
if (!this.nFont) return false;
for (var i = Card.CRTC.CURSOR_START.INDX; i <= Card.CRTC.CURSOR_ADDR_LO; i++) {
if (this.cardActive.regCRTData[i] == null)
return false;
}
var bCursorFlags = this.cardActive.regCRTData[Card.CRTC.CURSOR_START.INDX];
var bCursorStart = bCursorFlags & Card.CRTC.CURSOR_START.MASK;
var bCursorEnd = this.cardActive.regCRTData[Card.CRTC.CURSOR_END.INDX] & Card.CRTC.CURSOR_END.MASK;
var bCursorMax = this.cardActive.regCRTData[Card.CRTC.MAX_SCAN.INDX] & Card.CRTC.MAX_SCAN.MASK;
/*
* HACK: The original EGA BIOS has a cursor emulation bug when 43-line mode is enabled, so we attempt to detect
* that particular combination of bad values and automatically fix them (we're so thoughtful!)
*/
var fEGAHack = false;
if (this.cardActive === this.cardEGA) {
fEGAHack = true;
if (bCursorMax == 7 && bCursorStart == 4 && !bCursorEnd) bCursorEnd = 7;
}
/*
* One way of disabling the cursor is to set bit 5 (Card.CRTC.CURSOR_START.BLINKOFF) of the CRTC.CURSOR_START flags;
* another way is setting bCursorStart > bCursorEnd (unless it's an EGA, in which case we must actually draw a
* "split block" cursor instead).
*
* TODO: Verify whether the second test (bCursorStart > bCursorMax) should also result in a hidden cursor;
* ThinkTank sets both start and end values to 0x0f, which doesn't make sense on a CGA, where the max is 0x07.
*/
if ((bCursorFlags & Card.CRTC.CURSOR_START.BLINKOFF) || bCursorStart > bCursorEnd && !fEGAHack || bCursorStart > bCursorMax) {
this.removeCursor();
return false;
}
/*
* The most compatible way of disabling the cursor is to simply move the cursor to an off-screen position.
*/
var iCellCursor = (this.cardActive.regCRTData[Card.CRTC.CURSOR_ADDR_LO] + ((this.cardActive.regCRTData[Card.CRTC.CURSOR_ADDR_HI] & Card.CRTC.ADDR_HI_MASK) << 8));
if (this.iCellCursor != iCellCursor) {
if (MAXDEBUG && this.messageEnabled()) {
this.printMessage("checkCursor(): cursor moved from " + this.iCellCursor + " to " + iCellCursor);
}
this.removeCursor();
this.iCellCursor = iCellCursor;
}
/*
* yCursor and cyCursor are no longer scaled at this point, because the necessary scaling will depend on whether we're
* drawing the cursor to the on-screen or off-screen buffer, and updateChar() is in the best position to determine that.
*
* We also record cyCursorCell, the hardware cell height, since we'll need to know what the yCursor and cyCursor values
* are relative to when it's time to scale them.
*/
var bCursorSize = bCursorEnd - bCursorStart + 1;
if (this.yCursor != bCursorStart || this.cyCursor != bCursorSize) {
this.yCursor = bCursorStart;
this.cyCursor = bCursorSize;
}
this.cyCursorCell = bCursorMax + 1;
this.checkBlink();
return true;
};
/**
* removeCursor()
*
* @this {Video}
*/
Video.prototype.removeCursor = function()
{
if (this.iCellCursor >= 0) {
if (this.aCellCache !== undefined) {
var drawCursor = (Video.ATTRS.DRAW_CURSOR << 8);
var data = this.aCellCache[this.iCellCursor];
if (data & drawCursor) {
data &= ~drawCursor;
var col = this.iCellCursor % this.nCols;
var row = (this.iCellCursor / this.nCols)|0;
if (this.nFont && this.aFonts[this.nFont]) {
/*
* If we're using an off-screen buffer in text mode, then we need to keep it in sync with "reality".
*/
if (this.contextScreenBuffer) {
this.updateChar(col, row, data, this.contextScreenBuffer);
}
/*
* While updating the on-screen canvas directly could open us up to potential subpixel artifacts again,
* I'm hopeful that won't be the case, since removeCursor() is called only during certain well-defined
* events. The alternative to this simple updateChar() call is unappealing: redrawing the ENTIRE off-screen
* buffer to the on-screen canvas, just as updateScreen() does.
*/
this.updateChar(col, row, data);
}
if (MAXDEBUG && this.messageEnabled()) {
this.printMessage("removeCursor(): removed from " + row + "," + col);
}
this.aCellCache[this.iCellCursor] = data;
}
}
this.iCellCursor = -1;
}
};
/**
* getCardAccess()
*
* @this {Video}
* @return {number|undefined} current memory access setting, or undefined if unknown
*/
Video.prototype.getCardAccess = function()
{
var nAccess;
var card = this.cardActive;
this.fColor256 = false;
var regGRCMode = card.regGRCData[Card.GRC.MODE.INDX];
if (regGRCMode != null) {
var nReadAccess = Card.ACCESS.READ.MODE0;
var nWriteAccess = Card.ACCESS.WRITE.MODE0;
var nWriteMode = regGRCMode & Card.GRC.MODE.WRITE.MASK;
var regDataRotate = card.regGRCData[Card.GRC.DATAROT.INDX] & Card.GRC.DATAROT.MASK;
switch (nWriteMode) {
case Card.GRC.MODE.WRITE.MODE0:
if (regDataRotate) {
nWriteAccess = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.ROT;
switch (regDataRotate & Card.GRC.DATAROT.FUNC) {
case Card.GRC.DATAROT.AND:
nWriteAccess = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.AND;
break;
case Card.GRC.DATAROT.OR:
nWriteAccess = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.OR;
break;
case Card.GRC.DATAROT.XOR:
nWriteAccess = Card.ACCESS.WRITE.MODE0 | Card.ACCESS.WRITE.XOR;
break;
default:
break;
}
card.nDataRotate = regDataRotate & Card.GRC.DATAROT.COUNT;
}
break;
case Card.GRC.MODE.WRITE.MODE1:
nWriteAccess = Card.ACCESS.WRITE.MODE1;
break;
case Card.GRC.MODE.WRITE.MODE2:
switch (regDataRotate & Card.GRC.DATAROT.FUNC) {
default:
nWriteAccess = Card.ACCESS.WRITE.MODE2;
break;
case Card.GRC.DATAROT.AND:
nWriteAccess = Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.AND;
break;
case Card.GRC.DATAROT.OR:
nWriteAccess = Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.OR;
break;
case Card.GRC.DATAROT.XOR:
nWriteAccess = Card.ACCESS.WRITE.MODE2 | Card.ACCESS.WRITE.XOR;
break;
}
break;
case Card.GRC.MODE.WRITE.MODE3:
if (this.nCard == Video.CARD.VGA) {
nWriteAccess = Card.ACCESS.WRITE.MODE3;
card.nDataRotate = regDataRotate & Card.GRC.DATAROT.COUNT;
}
break;
default:
if (DEBUG && this.messageEnabled()) {
this.printMessage("getCardAccess(): invalid GRC mode (" + str.toHexByte(regGRCMode) + ")");
}
break;
}
if (regGRCMode & Card.GRC.MODE.READ.MODE1) {
nReadAccess = Card.ACCESS.READ.MODE1;
}
/*
* I discovered that when the IBM EGA ROM scrolls the screen in graphics modes 0x0D and 0x0E, it
* reprograms this register for WRITE.MODE1 (which is fine) *and* EVENODD (which is, um, very odd).
* Moreover, it does NOT make the complementary change to the SEQ.MEMMODE.SEQUENTIAL bit; under
* normal circumstances, those two bits are always supposed to programmed oppositely.
*
* Until I can perform some tests on real hardware, I have to assume that the EGA scroll operation
* is supposed to actually WORK in modes 0x0D and 0x0E, so I've decided to tie the trigger for my own
* EVENODD functions to SEQ.MEMMODE.SEQUENTIAL being clear, instead of GRC.MODE.EVENODD being set.
*
* It's also possible that my EVENODD read/write functions are not implemented properly; when EVENODD
* is in effect, which addresses get latched by a read, and to which addresses are latches written?
* If EVENODD has no effect on the effective address used with the latches, then I should change the
* EVENODD read/write functions accordingly.
*
* However, I've also done some limited testing with an emulated VGA running in text mode, and I've
* discovered that toggling the GRC.MODE.EVENODD bit *alone* doesn't seem to affect the delivery of
* text mode attributes from plane 1. So maybe this is the wiser change after all.
*
* TODO: Perform some tests on actual EGA/VGA hardware, to determine the proper course of action.
*
* if (regGRCMode & Card.GRC.MODE.EVENODD) {
* nReadAccess |= Card.ACCESS.READ.EVENODD;
* nWriteAccess |= Card.ACCESS.WRITE.EVENODD;
* }
*/
var regSEQMode = card.regSEQData[Card.SEQ.MEMMODE.INDX];
if (regSEQMode != null) {
if (!(regSEQMode & Card.SEQ.MEMMODE.SEQUENTIAL)) {
nReadAccess |= Card.ACCESS.READ.EVENODD;
nWriteAccess |= Card.ACCESS.WRITE.EVENODD;
}
if (regGRCMode & Card.GRC.MODE.COLOR256) {
if (regSEQMode & Card.SEQ.MEMMODE.CHAIN4) {
nReadAccess |= Card.ACCESS.READ.CHAIN4;
nWriteAccess |= Card.ACCESS.WRITE.CHAIN4;
}
this.fColor256 = true;
}
}
nAccess = nReadAccess | nWriteAccess;
}
return nAccess;
};
/**
* setCardAccess(nAccess)
*
* @this {Video}
* @param {number|undefined} nAccess (one of the Card.ACCESS.* constants)
* @return {boolean} true if access may have changed, false if not
*/
Video.prototype.setCardAccess = function(nAccess)
{
var card = this.cardActive;
if (card && nAccess != null && nAccess != card.nAccess) {
if (MAXDEBUG && this.messageEnabled()) {
this.printMessage("setCardAccess(" + str.toHexWord(nAccess) + ")");
}
card.setMemoryAccess(nAccess);
/*
* Note that setMemoryAccess() can fail, in which case it will an report error, indicating either a
* misconfiguration or some sort of internal inconsistency; in any case, there's not much we can do about
* it at this point, other than possibly reverting the current access setting. There's probably not much
* point, however, because there's no guarantee that setMemoryAccess() didn't modify one or more blocks
* before choking.
*/
this.bus.setMemoryAccess(card.addrBuffer, card.sizeBuffer, card.getMemoryAccess(), true);
return true;
}
return false;
};
/**
* setDimensions()
*
* This is the workhorse of setMode()
*
* @this {Video}
*/
Video.prototype.setDimensions = function()
{
this.nFont = 0;
this.nCols = this.nColsDefault;
this.nRows = this.nRowsDefault;
this.nColsLogical = this.nCols;
this.nCellsPerWord = Video.aModeParms[Video.MODE.MDA_80X25][2];
var cbPadding = 0;
var modeParms = Video.aModeParms[this.nMode];
if (modeParms) {
this.nCols = modeParms[0];
this.nRows = modeParms[1];
this.nCellsPerWord = modeParms[2];
cbPadding = modeParms[3]; // undefined for EGA/VGA graphics modes only
this.nFont = modeParms[4]; // this will be undefined for all graphics modes
if (this.nMonitorType == ChipSet.MONITOR.EGACOLOR || this.nMonitorType == ChipSet.MONITOR.VGACOLOR) {
/*
* When an EGA is connected to a CGA monitor, the old aModeParms table is correct: we must
* use the hard-coded 8x8 "CGA_80" font. But when it's connected to an EGA monitor, we want
* to use the 9x14 "EGA" color font instead.
*
* TODO: Can an EGA with a monochrome monitor be programmed for 43-line mode as well? If so,
* then we'll need to load another MDA font variation, because we only load the 9x14 font for MDA.
*/
if (this.cardActive === this.cardEGA && this.nFont == Video.FONT.CGA) {
if ((this.cardEGA.regCRTData[Card.CRTC.EGA.MAX_SCAN.INDX] & Card.CRTC.EGA.MAX_SCAN.SCAN_LINE) == 7) {
/*
* Vertical resolution of 350 divided by 8 (ie, scan lines 0-7) yields 43 whole rows.
*/
this.nRows = this.cardEGA.getCRTCReg(Card.CRTC.EGA.VDISP_END) < 350? 43 : 50;
}
/*
* Since we can also be called before any hardware registers have been initialized,
* it may be best to not perform the following test (which is why it's commented out).
*/
else /* if (this.cardEGA.regCRTData[Card.CRTC.EGA.MAX_SCAN.INDX] == 13) */ {
/*
* Vertical resolution of 350 divided by 14 (ie, scan lines 0-13) yields exactly 25 rows.
*
* Note that a card's default font matches its card ID (eg, Video.CARD.EGA == Video.FONT.EGA,
* and Video.CARD.VGA == Video.FONT.VGA)
*/
this.nFont = this.nCard;
}
}
}
}
this.nCells = (this.nCols * this.nRows)|0;
this.nCellCache = (this.nCells / this.nCellsPerWord)|0;
this.cbScreen = this.nCellCache;
this.cbSplit = 0;
if (cbPadding !== undefined) {
this.cbScreen = ((this.cbScreen << 1) + cbPadding)|0;
this.cbSplit = (this.cbScreen + cbPadding) >> 1;
}
/*
* If no fonts were successfully loaded, there's no point in initializing the remaining drawing parameters.
*/
if (!this.aFonts.length) return;
this.cxScreenCell = (this.cxScreen / this.nCols)|0;
this.cyScreenCell = (this.cyScreen / this.nRows)|0;
/*
* Now we make the all-important scaling determination: if the font cell dimensions (cxCell, cyCell)
* don't match the physical screen cell dimensions (cxCell, cyCell), then we look at the caller's
* fScaleFont setting: if it's false, we draw the characters as-is, with a border if the characters
* are smaller than the cells; and if fScaleFont is true, we simply tell drawImage to draw the
* characters to fit.
*
* WARNING: The only problem with fScaleFont is that any stretching or shrinking tends to be accompanied
* by subpixel artifacts along the boundaries of the font images. Definitely annoying, and apparently
* there are no standard mechanisms for turning that behavior off. So, for now, I've "neutered" the
* fScaleFont test slightly, by adding the "nCols == 80" test that prevents scaling from kicking in for
* 40-column modes.
*
* Also, whether scaling or not, if it makes sense to use a "doubled" font, we'll switch the font as
* well. Note that the doubled font for any existing font also has an ID that is double the existing ID,
* making it easy to check for the existence of a font's "double" (shift the ID left by 1).
*
* TODO: Since we now use an off-screen buffer for ALL modes, both text and graphics, we should
* revisit changes that were made to work around subpixel artifacts; those should no longer be an issue.
*/
if (this.nFont) {
var font = this.aFonts[this.nFont];
if (!font) {
this.assert(false);
return;
}
var fontDoubled = this.aFonts[this.nFont << 1];
if (this.fScaleFont && this.nCols == 80) {
if (fontDoubled) {
if (this.cxScreenCell >= (fontDoubled.cxCell * 3) >> 2) { // && this.cyScreenCell > (fontDoubled.cyCell * 3) >> 2) {
this.nFont <<= 1;
font = fontDoubled;
if (DEBUG) this.log("setDimensions(): switching to double-size font, scaled");
}
}
} else {
if (fontDoubled) {
if (this.cxScreenCell >= fontDoubled.cxCell) { // && this.cyScreenCell == fontDoubled.cyCell) {
this.nFont <<= 1;
font = fontDoubled;
if (DEBUG) this.log("setDimensions(): switching to double-size font, unscaled");
}
}
if (!this.fScaleFont) {
this.cxScreenCell = font.cxCell;
this.cyScreenCell = font.cyCell;
}
}
/*
* In text modes, we have the option of setting all the *ScreenBuffer variables to null instead of
* allocating them, because updateChar(), as currently written, is capable of writing characters to
* either an off-screen or on-screen context.
*
* this.imageScreenBuffer = this.canvasScreenBuffer = this.contextScreenBuffer = null;
*/
this.cxBuffer = this.cyBuffer = 0;
if (font) {
this.cxBuffer = this.nCols * font.cxCell;
this.cyBuffer = this.nRows * font.cyCell;
}
} else {
/*
* CGA graphics modes have their "cells" (pixels) split evenly across two halves of the video buffer, with
* EVEN scan lines in the first half and ODD scan lines in the second half, so unlike text modes, we can't set a
* limit of what's visible on-screen to "columns * rows", so the screen limit is set to match the buffer limit.
*
* In addition, updateScreen() requires an off-screen imageData buffer that matches the size of the entire screen,
* so that updateScreen() can set all pixels that have changed and then update the screen with a single drawImage().
*
* An alternative approach, with a smaller footprint, would be to allocate an off-screen buffer large enough for a
* single scan line, and redraw one scan line at a time, but given how EVEN and ODD scan lines are spread across the
* entire buffer, it's not clear there would be enough unchanged scan lines on average to make that approach faster.
*/
this.cxScreenCell = this.cyScreenCell = 1; // in graphics mode, a cell is exactly one pixel
this.cxBuffer = this.nCols;
this.cyBuffer = this.nRows;
}
/*
* Allocate the off-screen buffers
*/
this.imageScreenBuffer = this.contextScreen.createImageData(this.cxBuffer, this.cyBuffer);
this.canvasScreenBuffer = document.createElement("canvas");
this.canvasScreenBuffer.width = this.cxBuffer;
this.canvasScreenBuffer.height = this.cyBuffer;
this.contextScreenBuffer = this.canvasScreenBuffer.getContext("2d");
/*
* Since cxCell and cyCell were originally defined in terms of cxScreen/nCols and cyScreen/nRows, you might think
* these border calculations would always be zero, but that would mean you overlooked the code above which tries to
* avoid stretching 40-column modes into an unpleasantly wide shape.
*/
this.xScreenOffset = this.yScreenOffset = 0;
this.cxScreenOffset = this.cxScreen;
this.cyScreenOffset = this.cyScreen;
var cxBorder = this.cxScreen - (this.nCols * this.cxScreenCell);
var cyBorder = this.cyScreen - (this.nRows * this.cyScreenCell);
if (cxBorder > 0) {
this.xScreenOffset = (cxBorder >> 1);
this.cxScreenOffset -= cxBorder;
}
if (cyBorder > 0) {
this.yScreenOffset = (cyBorder >> 1);
this.cyScreenOffset -= cyBorder;
}
if (cxBorder || cyBorder) {
this.contextScreen.fillStyle = this.canvasScreen.style.backgroundColor;
this.contextScreen.fillRect(0, 0, this.cxScreen, this.cyScreen);
}
};
/**
* checkMode(fForce)
*
* Called whenever the MDA/CGA's mode register (eg, Card.MDA.MODE.PORT, Card.CGA.MODE.PORT) is updated,
* or whenever the EGA/VGA's GRC.MISC register is updated, or when we've just finished a restore().
*
* @this {Video}
* @param {boolean} [fForce] is used to force a mode update, if we recognize the current mode
* @return {boolean} true if successful, false if not
*/
Video.prototype.checkMode = function(fForce)
{
var nAccess;
var nMode = this.nMode;
var card = this.cardActive;
if (!card) {
/*
* We are likely being called after a restore(), which needs us to call setMode() to insure the proper video
* buffer is mapped in. So we unset this.nMode to guarantee that setMode() will be called, and if it wasn't set
* to anything before, then we fall-back to the default mode.
*/
this.nMode = null;
if (nMode == null) nMode = this.nModeDefault;
}
else {
if (card.nCard == Video.CARD.MDA) {
nMode = Video.MODE.MDA_80X25;
}
else if (card.nCard >= Video.CARD.EGA) {
/*
* The sizeBuffer we choose reflects the amount of physical address space that all 4 planes
* of EGA memory normally span, NOT the total amount of EGA memory. So for a 64Kb EGA card,
* we would set card.sizeBuffer to 16Kb (0x4000).
*
* TODO: Need to take into account modes that "chain" planes together (eg, mode 0x0F, and
* presumably mode 0x10, on an EGA card with only 64Kb).
*/
nMode = null;
var cbBuffer = card.cbMemory >> 2;
var cbBufferText = (cbBuffer > 0x8000? 0x8000 : cbBuffer);
var regGRCMisc = card.regGRCData[Card.GRC.MISC.INDX];
if (regGRCMisc != null) {
switch(regGRCMisc & Card.GRC.MISC.MAPMEM) {
case Card.GRC.MISC.MAPA0128:
card.addrBuffer = 0xA0000;
card.sizeBuffer = cbBuffer; // 0x20000
nMode = Video.MODE.UNKNOWN; // no BIOS mode uses this mapping, but we don't want to leave nMode null if we've come this far
break;
case Card.GRC.MISC.MAPA064:
card.addrBuffer = 0xA0000;
card.sizeBuffer = cbBuffer; // 0x10000
nMode = (this.nMonitorType == ChipSet.MONITOR.MONO? Video.MODE.EGA_640X350_MONO : Video.MODE.EGA_640X350);
break;
case Card.GRC.MISC.MAPB032:
card.addrBuffer = 0xB0000;
card.sizeBuffer = cbBufferText;
nMode = Video.MODE.MDA_80X25;
break;
case Card.GRC.MISC.MAPB832:
card.addrBuffer = 0xB8000;
card.sizeBuffer = cbBufferText;
nMode = (this.nMonitorType == ChipSet.MONITOR.MONO? Video.MODE.CGA_80X25_BW : Video.MODE.CGA_80X25);
break;
default:
break;
}
/*
* TODO: The following mode discrimination code is all a bit haphazard, a byproduct of its slow evolution
* from increasingly greater EGA support to increasingly greater VGA support. Make it more rational someday,
* so that as support is added for even more modes (eg, "Mode X" variations, monochrome modes, etc), it
* doesn't get totally out of control.
*
* One of the problems with the current approach is that it depends on the card's registers being programmed
* in at least roughly the same order that the IBM EGA and VGA ROMs program them.
*/
var regGRCMode = card.regGRCData[Card.GRC.MODE.INDX];
/*
* This text/graphics hybrid test detects the way Windows 95 reprograms the VGA on boot; ie, switching
* to graphics mode 0x13 (320x200) without disturbing the text buffer contents, then reprogramming it
* to enable graphics mode 0x15 (320x400), then drawing a logo in the 2nd half of the video memory, and
* finally reprogramming regGRCMode and regGRCMisc to move the frame buffer back to its original text mode
* location.
*/
var fTextGraphicsHybrid = (regGRCMode & (Card.GRC.MODE.COLOR256 | Card.GRC.MODE.EVENODD)) == (Card.GRC.MODE.COLOR256 | Card.GRC.MODE.EVENODD);
if (fTextGraphicsHybrid) {
/*
* When fTextGraphicsHybrid is true, we should be at the end of the above process, so addrBuffer
* will have changed. Since we don't (yet) assign a special mode to that configuration, we must at
* least set fForce to true, so that setMode() will notice the buffer address change and remap it.
*/
if (card.addrBuffer != this.addrBuffer || card.sizeBuffer != this.sizeBuffer) {
fForce = true;
}
}
var nCRTCVertTotal = card.getCRTCReg(Card.CRTC.EGA.VTOTAL);
var nCRTCMaxScan = card.regCRTData[Card.CRTC.EGA.MAX_SCAN.INDX];
var nCRTCModeCtrl = card.regCRTData[Card.CRTC.EGA.MODE_CTRL.INDX];
var fSEQDotClock = (card.regSEQData[Card.SEQ.CLOCKING.INDX] & Card.SEQ.CLOCKING.DOTCLOCK);
if (nMode != Video.MODE.UNKNOWN) {
if (!(regGRCMisc & Card.GRC.MISC.GRAPHICS)) {
/*
* Here's where we handle text modes; since nMode will have been assigned a default
* of either 0x02 or 0x03, convert that to either 0x05 or 0x04 if we're in a low-res
* graphics mode, 0x06 otherwise.
*/
nMode -= (fSEQDotClock? 2 : 0);
}
else if (card.addrBuffer != 0xA0000 && !fTextGraphicsHybrid && !(nCRTCModeCtrl & Card.CRTC.EGA.MODE_CTRL.COMPAT_MODE)) {
/*
* Here's where we handle CGA graphics modes; since nMode will have been assigned a
* default of either 0x02 or 0x03, convert that to either 0x05 or 0x04 if we're in a
* low-res graphics mode, 0x06 otherwise.
*
* For Windows 95, I've had to add BOTH the fTextGraphicsHybrid test, to avoid misdetecting
* the logo display mode, AND the COMPAT_MODE test, to avoid misinterpreting the VDD's physical
* (NOT logical) card reprogramming during windowed VM creation; the latter seems like a VDD bug,
* because only the Windows display driver should be *physically* reprogramming the card then.
*/
nMode = fSEQDotClock? (7 - nMode) : Video.MODE.CGA_640X200;
} else {
/*
* Here's where we handle EGA/VGA graphics modes, discriminating among modes 0x0D and up;
* we've already defaulted to either 0x0F or 0x10. If COLOR256 is set, then select mode
* 0x13 (or greater), else if 200-to-400 scan-line conversion is in effect, select either
* mode 0x0D or 0x0E, else if VGA resolution is set, select either mode 0x11 or 0x12.
*/
if (card.regGRCData[Card.GRC.MODE.INDX] & Card.GRC.MODE.COLOR256) {
if (nCRTCMaxScan & Card.CRTC.EGA.MAX_SCAN.SCAN_LINE) {
/*
* NOTE: Technically, VDISP_END is one of those CRTC registers that should be read using
* card.getCRTCReg(), because there are overflow bits (8 and 9). However, all known modes
* always SET bit 8 and CLEAR bit 9, so examining only bits 0-7 is sorta OK.
*/
if (card.regCRTData[Card.CRTC.EGA.VDISP_END] <= 0x8F) {
nMode = Video.MODE.VGA_320X200;
}
else { /* (card.regCRTData[Card.CRTC.EGA.VDISP_END] == 0xDF) */
nMode = Video.MODE.VGA_320X240;
}
} else {
nMode = Video.MODE.VGA_320X400;
}
}
else if ((nCRTCMaxScan & Card.CRTC.EGA.MAX_SCAN.CONVERT400) || nCRTCVertTotal < 350) {
nMode = (fSEQDotClock? Video.MODE.EGA_320X200 : Video.MODE.EGA_640X200);
} else if (nCRTCVertTotal >= 480) {
nMode = (this.nMonitorType == ChipSet.MONITOR.MONO? Video.MODE.VGA_640X480_MONO : Video.MODE.VGA_640X480);
}
if (DEBUG && this.messageEnabled()) {
this.printMessage("checkMode(): nCRTCVertTotal=" + nCRTCVertTotal + ", mode=" + str.toHexByte(nMode));
}
}
}
nAccess = this.getCardAccess();
}
}
else if (card.regMode & Card.CGA.MODE.VIDEO_ENABLE) {
/*
* NOTE: For the CGA, we precondition any mode change on CGA.MODE.VIDEO_ENABLE being set, otherwise
* we'll get spoofed by the ROM BIOS scroll code, which waits for vertical retrace and then turns CGA.MODE.VIDEO_ENABLE
* off, using a hard-coded mode value (0x25) that does NOT necessarily match the the CGA video mode currently in effect.
*/
if (!(card.regMode & Card.CGA.MODE.GRAPHIC_SEL)) {
nMode = ((card.regMode & Card.CGA.MODE._80X25)? Video.MODE.CGA_80X25 : Video.MODE.CGA_40X25);
if (card.regMode & Card.CGA.MODE.BW_SEL) nMode -= 1;
} else {
nMode = ((card.regMode & Card.CGA.MODE.HIRES_BW)? Video.MODE.CGA_640X200 : Video.MODE.CGA_320X200_BW);
if (!(card.regMode & Card.CGA.MODE.BW_SEL)) nMode -= 1;
}
}
}
/*
* NOTE: If setMode() remaps the video memory, that will trigger calls to setCardAccess() to also update the
* memory's access functions. However, if the memory access setting (nAccess) is about to change as well, those
* changes will be moot until the setCardAccess() call that follows. Basically, whenever both memory mapping AND
* access functions are changing, the memory will be in an inconsistent state until both setMode() and setCardAccess()
* are finished.
*
* The setMode() call takes precedence; if we called setCardAccess() first, it might attempt to modify memory access
* functions based on the card's addrBuffer setting, and if that doesn't match what's currently mapped, assertions
* will be triggered (probably not fatal, but it would defeat the point of the assertions).
*/
if (!this.setMode(nMode, fForce)) return false;
this.setCardAccess(nAccess);
return true;
};
/**
* setMode(nMode, fForce)
*
* Set fForce to true to update the mode regardless of previous mode, or false to perform
* a normal update that bypasses updateScreen() but still calls initCache().
*
* @this {Video}
* @param {number|null} nMode
* @param {boolean|undefined} [fForce] is set when checkMode() wants to force a mode update
* @return {boolean} true if successful, false if failure
*/
Video.prototype.setMode = function(nMode, fForce)
{
if (nMode != null && (nMode != this.nMode || fForce)) {
if (DEBUG && this.messageEnabled()) {
this.printMessage("setMode(" + str.toHexByte(nMode) + (fForce? ",force" : "") + ")", true, true);
}
this.cUpdates = 0; // count updateScreen() calls as a means of driving blink updates
this.nMode = nMode;
this.fRGBValid = false;
/*
* On an EGA, it's CRITICAL that a reset() invalidate cardActive, to ensure that the code below
* releases the previous video buffer and installs a new one, even if there was no change in the
* video buffer address or size, because otherwise the Memory blocks installed at the video buffer
* address may still be using blocks of the EGA's previous memory buffer.
*
* When the EGA is reinitialized, a new memory buffer (adwMemory) is allocated (see initEGA()), and
* this is where the mapping of that EGA memory buffer to the video buffer occurs. Other cards
* (MDA or CGA) don't allocate/manage their own memory buffer, but even then, it's still a good idea
* to always force this operation (eg, in case a switch setting changed the active video card).
*/
var card = this.cardActive || (nMode == Video.MODE.MDA_80X25? this.cardMono : this.cardColor);
if (card != this.cardActive || card.addrBuffer != this.addrBuffer || card.sizeBuffer != this.sizeBuffer) {
this.removeCursor();
if (this.addrBuffer) {
if (DEBUG && this.messageEnabled()) {
this.printMessage("setMode(" + str.toHexByte(nMode) + "): removing " + str.toHexLong(this.sizeBuffer) + " bytes from " + str.toHexLong(this.addrBuffer));
}
if (!this.bus.removeMemory(this.addrBuffer, this.sizeBuffer)) {
/*
* TODO: Force this failure case and see how well the Video component deals with it.
*/
return false;
}
if (this.cardActive) this.cardActive.fActive = false;
}
this.cardActive = card;
card.fActive = true;
this.addrBuffer = card.addrBuffer;
this.sizeBuffer = card.sizeBuffer;
if (DEBUG && this.messageEnabled()) {
this.printMessage("setMode(" + str.toHexByte(nMode) + "): adding " + str.toHexLong(this.sizeBuffer) + " bytes to " + str.toHexLong(this.addrBuffer));
}
var controller = (card === this.cardEGA? card : null);
if (!this.bus.addMemory(card.addrBuffer, card.sizeBuffer, Memory.TYPE.VIDEO, controller)) {
/*
* TODO: Force this failure case and see how well the Video component deals with it.
*/
return false;
}
}
this.setDimensions();
this.invalidateCache(true);
this.updateScreen();
}
return true;
};
/**
* setPixel(imageData, x, y, rgb)
*
* Worker function used by createFontColor() and updateScreen() (graphics modes only).
*
* @this {Video}
* @param {Object} imageData
* @param {number} x
* @param {number} y
* @param {Array.<number>} rgb is a 4-element array containing the red, green, blue and alpha values
*/
Video.prototype.setPixel = function(imageData, x, y, rgb)
{
var index = (x + y * imageData.width) * rgb.length;
imageData.data[index] = rgb[0];
imageData.data[index+1] = rgb[1];
imageData.data[index+2] = rgb[2];
imageData.data[index+3] = rgb[3];
};
/**
* initCache()
*
* Initializes the contents of our internal cell cache.
*
* TODO: Consider changing this to a cache of RGB values, so that when the buffer is merely being color-cycled,
* we don't have to update the entire screen. This will also allow invalidateCache() to honor the fModified flag,
* bypassing initCache() when it is false.
*
* @this {Video}
*/
Video.prototype.initCache = function()
{
this.cBlinkVisible = -1; // invalidate the visible blinking character count, to force updateScreen() to recount
this.fCellCacheValid = false;
var nCells = this.nCellCache;
if (this.aCellCache === undefined || this.aCellCache.length != nCells) {
this.aCellCache = new Array(nCells);
}
};
/**
* invalidateCache(fModified)
*
* Ensure that the next updateScreen() will update every cell; intended for situations where the entire screen needs
* to be redrawn, even though the underlying data in the video buffer has not changed (and therefore cleanMemory() will
* report that the buffer is still clean, and/or all the video data still matches everything in our cell cache).
*
* For example, when the palette is being cycled, the screen is being panned, the page is being flipped, etc.
*
* @this {Video}
* @param {boolean} [fModified] (true if the buffer may have been modified, false if only color(s) may have changed)
*/
Video.prototype.invalidateCache = function(fModified)
{
if (!fModified) this.fRGBValid = false;
this.initCache();
};
/**
* doBlink()
*
* This function is obsolete, now that the checkBlink() function is called on every updateScreen()
* and checkCursor() call. updateScreen() is driven by CPU bursts, so piggy-backing on that to drive
* blink updates seems preferable to having another active timer in the system.
*
* @this {Video}
* @param {boolean} [fStart]
*
Video.prototype.doBlink = function(fStart)
{
if (this.cBlinks >= 0) {
this.cBlinks++;
if (this.cBlinkVisible || this.iCellCursor >= 0) {
if (!fStart && !this.cpu.isRunning()) {
this.updateScreen();
}
setTimeout(function(video) { return function onBlinkTimeout() {video.doBlink();}; }(this), 266);
return;
}
this.cBlinks = -1;
}
},
*/
/**
* updateChar(col, row, data, context)
*
* Updates a particular character cell (row,col) in the associated window.
*
* The data parameter is the attribute byte from the display buffer (fgnd attribute in the low nibble,
* bgnd attribute in the high nibble), but updateScreen() supplements data with a couple internal attribute bits:
*
* ATTRS.DRAW_FGND: set for every cell whose fgnd element is currently on (ie, non-blinking, or whenever blink is on)
* ATTRS.DRAW_CURSOR: set only for the cell containing the cursor, if any
*
* To make a character blink, we alternately draw its cell with ATTRS.DRAW_FGND set, and then again with
* ATTRS.DRAW_FGND clear (meaning only the cell background is drawn).
*
* To make the cursor blink, we must alternately draw its entire cell with ATTRS.DRAW_CURSOR set, and then
* draw it again with ATTRS.DRAW_CURSOR clear.
*
* @this {Video}
* @param {number} col
* @param {number} row
* @param {number} data (if text mode, character code in low byte, attribute code in high byte)
* @param {Object} [context]
*/
Video.prototype.updateChar = function(col, row, data, context)
{
/*
* The caller MUST promise this.nFont is defined, and that the font in this.aFonts[this.nFont] has been loaded.
*/
var bChar = data & 0xff;
var bAttr = data >> 8;
var iFgnd = bAttr & 0xf;
var font = this.aFonts[this.nFont];
if (font.aColorMap) iFgnd = font.aColorMap[iFgnd];
/*
* Just as aColorMap maps the foreground attribute to the appropriate foreground character grid,
* it also maps the background attribute to the appropriate background color.
*/
var xDst, yDst;
var iBgnd = (bAttr >> 4) & 0xf;
if (font.aColorMap) iBgnd = font.aColorMap[iBgnd];
if (context) {
xDst = col * font.cxCell;
yDst = row * font.cyCell;
context.fillStyle = font.aCSSColors[iBgnd];
context.fillRect(xDst, yDst, font.cxCell, font.cyCell);
} else {
xDst = col * this.cxScreenCell + this.xScreenOffset;
yDst = row * this.cyScreenCell + this.yScreenOffset;
this.contextScreen.fillStyle = font.aCSSColors[iBgnd];
this.contextScreen.fillRect(xDst, yDst, this.cxScreenCell, this.cyScreenCell);
}
if (MAXDEBUG && this.messageEnabled(Messages.VIDEO | Messages.LOG)) {
this.log("updateCharBgnd(" + col + "," + row + "," + bChar + "): filled " + xDst + "," + yDst);
}
if (bAttr & Video.ATTRS.DRAW_FGND) {
/*
* (bChar & 0xf) is the equivalent of (bChar % 16), and (bChar >> 4) is the equivalent of Math.floor(bChar / 16)
*/
var xSrcFgnd = (bChar & 0xf) * font.cxCell;
var ySrcFgnd = (bChar >> 4) * font.cyCell;
if (MAXDEBUG && this.messageEnabled(Messages.VIDEO | Messages.LOG)) {
this.log("updateCharFgnd(" + col + "," + row + "," + bChar + "): draw from " + xSrcFgnd + "," + ySrcFgnd + " (" + font.cxCell + "," + font.cyCell + ") to " + xDst + "," + yDst);
}
if (context) {
context.drawImage(font.aCanvas[iFgnd], xSrcFgnd, ySrcFgnd, font.cxCell, font.cyCell, xDst, yDst, font.cxCell, font.cyCell);
} else {
this.contextScreen.drawImage(font.aCanvas[iFgnd], xSrcFgnd, ySrcFgnd, font.cxCell, font.cyCell, xDst, yDst, this.cxScreenCell, this.cyScreenCell);
}
}
if (bAttr & Video.ATTRS.DRAW_CURSOR) {
/*
* Drawing the cursor with lineTo() seemed logical, but it was complicated by the fact that the
* TOP of the line must appear at "yDst + this.yCursor", whereas lineTo() wants to know the CENTER
* of the line. So it's simpler to draw the cursor with another fillRect(). Here's the old code:
*
* this.contextScreen.strokeStyle = font.aCSSColors[iFgnd];
* this.contextScreen.lineWidth = this.cyCursor;
* this.contextScreen.beginPath();
* this.contextScreen.moveTo(xDst, yDst + this.yCursor);
* this.contextScreen.lineTo(xDst + this.cxScreenCell, yDst + this.yCursor);
* this.contextScreen.stroke();
*
* Also, note that we're scaling the yCursor and cyCursor values here, instead of in checkCursor(), because
* this is where we have all the required information: in the first case (off-screen buffer), the scaling must
* be based on the font cell size (cxCell, cyCell), whereas in the second case (on-screen buffer), the scaling
* must be based on the screen cell size (cxScreenCell,cyScreenCell).
*
* yCursor and cyCursor are actual hardware values, both relative to another hardware value: cyCursorCell.
*/
var yCursor = this.yCursor;
var cyCursor = this.cyCursor;
if (context) {
if (this.cyCursorCell && this.cyCursorCell !== font.cyCell) {
yCursor = ((yCursor * font.cyCell) / this.cyCursorCell)|0;
cyCursor = ((cyCursor * font.cyCell) / this.cyCursorCell)|0;
}
context.fillStyle = font.aCSSColors[iFgnd];
context.fillRect(xDst, yDst + yCursor, font.cxCell, cyCursor);
} else {
if (this.cyCursorCell && this.cyCursorCell !== this.cyScreenCell) {
yCursor = ((yCursor * this.cyScreenCell) / this.cyCursorCell)|0;
cyCursor = ((cyCursor * this.cyScreenCell) / this.cyCursorCell)|0;
}
this.contextScreen.fillStyle = font.aCSSColors[iFgnd];
this.contextScreen.fillRect(xDst, yDst + yCursor, this.cxScreenCell, cyCursor);
}
}
};
/**
* updateScreen(fForce)
*
* Propagates the video buffer to the cell cache and updates the screen with any changes. Forced updates
* are generally internal updates triggered by an I/O operation or other state change, while non-forced updates
* are the periodic updates coming from the CPU.
*
* For every cell in the video buffer, compare it to the cell stored in the cell cache, render if it differs,
* and then update the cell cache to match. Since initCache() sets every cell in the cell cache to an
* invalid value, we're assured that the next call to updateScreen() will redraw the entire (visible) video buffer.
*
* @this {Video}
* @param {boolean} [fForce] is used by setMode() to reset the cell cache and force a redraw
*/
Video.prototype.updateScreen = function(fForce)
{
/*
* The Computer component maintains the fPowered setting on our behalf, so we use it.
*/
if (!this.flags.fPowered) return;
/*
* If the card's video signal is disabled (eg, during a mode change), then skip the update,
* unless fForce is set.
*/
var fEnabled = false;
var card = this.cardActive;
if (card) {
if (card !== this.cardEGA) {
if (card.regMode & Card.CGA.MODE.VIDEO_ENABLE) fEnabled = true;
}
else {
if (card.regATCIndx & Card.ATC.INDX_PAL_ENABLE) fEnabled = true;
}
}
if (!fEnabled && !fForce) return;
if (fForce) {
this.initCache();
}
else {
/*
* This should never happen, but since updateScreen() is also called by CPU.updateVideo(),
* better safe than sorry.
*/
if (this.aCellCache === undefined) return;
}
/*
* If cBlinks is "enabled" (ie, >= 0), then advance it once every 16 updateScreen() calls
* (assuming an updateScreen() frequency of 60 per second; see CPU.VIDEO_UPDATES_PER_SECOND).
*
* We assume that the CPU is calling us whenever fForce is undefined.
*/
var fBlinkUpdate = false;
if (!fForce && !(++this.cUpdates & 0xf) && this.cBlinks >= 0) {
this.cBlinks++;
fBlinkUpdate = true;
}
var iCell = 0;
var nCells = this.nCells;
/*
* Calculate the VISIBLE start of screen memory (addrScreen), not merely the PHYSICAL start,
* as well as the extent of it (cbScreen) and use those values for all addressing operations to follow.
* FYI, in these calculations, offScreen does not refer to "off-screen" memory, but rather the "offset"
* of the start of visible screen memory.
*/
var addrBuffer = this.addrBuffer;
var addrScreen = addrBuffer;
var addrScreenLimit = addrScreen + this.sizeBuffer;
/*
* HACK: To deal with the fTextGraphicsHybrid 320x400 mode that Windows 95 uses (ie, when the buffer
* is mapped to B800:0000 instead of A000:0000 and is configured for text mode access, but graphics are
* still being displayed from the second half of video memory), we must ignore the programmed address.
*
* In that case, the hard-coded address range below isn't actually active either, but it doesn't matter;
* we just have to get through the rest of this function and make it to the updateScreenGraphicsVGA() call,
* which will draw from our video buffer (adwMemory) directly; these addresses are only used for bounds
* checking.
*/
if (this.nMode >= Video.MODE.VGA_320X200) {
addrBuffer = addrScreen = 0xA0000;
addrScreenLimit = addrScreen + 0x10000;
}
/*
* HACK: The CRTC's START_ADDR_HI and START_ADDR_LO registers are supposed to be "latched" into
* offStartAddr ONLY at the start of every VRETRACE interval; this is an attempt to honor that behavior,
* but unfortunately, updateScreen() is currently called at the CPU's discretion, not necessarily in
* sync with nCyclesVertPeriod. As a result, we must rely on other criteria, like the number of vertical
* periods that have elapsed since the last CRTC write, writes to the ATC (see outATC()), etc.
*
* TODO: Consider matching the CPU's nCyclesNextVideoUpdate to the card's nCyclesVertPeriod, ensuring
* that CPU bursts are in sync with VRETRACE. Note, however, that that will be complicated by other
* factors, such as the horizontal retrace interval, and the timing requirements of other cards in a
* multi-display configuration.
*/
if ((this.getRetraceBits(card) & Card.CGA.STATUS.VRETRACE) || card.nVertPeriodsStartAddr && card.nVertPeriodsStartAddr < card.nVertPeriods) {
/*
* PARANOIA: Don't call invalidateCache() unless the address we're about to "latch" actually changed.
*/
var offStartAddr = ((card.regCRTData[Card.CRTC.START_ADDR_HI] << 8) + card.regCRTData[Card.CRTC.START_ADDR_LO])|0;
if (card.offStartAddr !== offStartAddr) {
card.offStartAddr = offStartAddr;
this.invalidateCache();
}
card.nVertPeriodsStartAddr = 0;
}
var offScreen = card.offStartAddr;
/*
* Any screen (aka "page") offset must be doubled for text modes, due to the attribute bytes.
* TODO: Come up with a more robust method of deciding when any screen offset should be doubled.
*/
if (this.nFont) offScreen <<= 1;
addrScreen += offScreen;
var cbScreen = this.cbScreen;
if (this.nCard >= Video.CARD.EGA && card.regCRTData[Card.CRTC.EGA.OFFSET] && (card.regCRTData[Card.CRTC.EGA.OFFSET] << 1) != card.regCRTData[Card.CRTC.EGA.HDISP_END] + 1) {
/*
* Pre-EGA, the extent of visible screen memory (cbScreen) was derived from nCols * nRows, but since
* then, the logical width of screen memory (nColsLogical) can differ from the visible width (nCols).
* We now calculate the logical width, and the compute a new cbScreen in much the same way the original
* cbScreen was computed (but without any CGA-related padding considerations).
*
* TODO: I'm taking a lot of shortcuts in this calculation (eg, relying on nFont to detect text modes,
* ignoring MODE_CTRL.BYTE_MODE, etc); generalize this someday. In addition, dividing the total number of
* cells by nCellsPerWord yields total WORDS, not BYTES, so we need to double cbScreen -- EXCEPT that the
* notion of cell has a slightly different meaning for EGA and VGA-specific modes. nCellsPerWord should
* not be overloaded like that.
*/
this.nColsLogical = card.regCRTData[Card.CRTC.EGA.OFFSET] << (this.nFont? 1 : (card.regCRTData[Card.CRTC.EGA.UNDERLINE.INDX] & Card.CRTC.EGA.UNDERLINE.DWORD)? 3 : 4);
cbScreen = ((this.nColsLogical * (this.nRows-1) + this.nCols) / this.nCellsPerWord)|0;
if (this.nMode <= Video.MODE.MDA_80X25) cbScreen <<= 1;
}
if (addrScreen + cbScreen > addrScreenLimit) {
cbScreen = addrScreenLimit - addrScreen;
if (cbScreen < 0) cbScreen = 0;
}
/*
* addrScreenLimit was initially the limit of the entire video buffer, but we now adjust it
* to the limit of what's visible, since that's all we want to draw.
*/
addrScreenLimit = addrScreen + cbScreen;
/*
* This next bit of code can be completely disabled if we discover problems with the dirty
* memory block tracking feature, or if we need to remove or disable that feature in the future.
*
* We use cleanMemory() to check the video buffer's dirty state. If the buffer is clean
* AND there are no visible blinking characters (as of the last updateScreen) AND there is
* no visible cursor, then we're done; simply return. Otherwise, if there's only a blinking
* cursor, then update JUST that one cell.
*
* When dealing with blinking characters, note that we need to run through the entire buffer
* ONLY if the low bits of the blink count just transitioned to 2 or 0; hence, we could return if
* the blink count was ODD. But we'd still have to worry about the cursor, so it's simpler to blow
* that small optimization off. Further optimizations are certainly possible, such as a hash table
* of all blinking character locations, but all those optimizations are saved for a rainy day.
*/
if (!fForce && this.fCellCacheValid && this.bus.cleanMemory(addrScreen, cbScreen)) {
if (!fBlinkUpdate) return;
if (!this.cBlinkVisible) {
/*
* Note that since iCellCursor is a cell-based (not byte-based) index, we must subtract
* offStartAddr, which is also cell-based; subtracting offScreen would not be appropriate,
* as it has already been converted to a byte-based offset (remember that in text modes,
* cell are words, not bytes).
*/
iCell = this.iCellCursor - card.offStartAddr;
/*
* Note that iCellCursor may have already been negative (-1 hides the cursor), and
* since offStartAddr should never be negative, we only need one iCell underflow check.
*/
if (iCell < 0) return;
nCells = iCell + 1;
}
// else if (this.cBlinks & 0x1) return;
}
if (this.nFont) {
/*
* This is the text-mode update case. We're required to FIRST verify that the current font
* has been successfully loaded, because we're not allowed to call updateChar() if there's no font.
*/
if (this.aFonts[this.nFont]) {
this.updateScreenText(addrScreen, addrScreenLimit, iCell, nCells);
this.checkBlink();
}
}
else if (this.cbSplit) {
/*
* All CGA graphics modes have the goofy split-buffer layout, hence the simple test above.
*/
this.updateScreenGraphicsCGA(addrScreen, addrScreenLimit);
}
else if (!this.fColor256) {
/*
* All EGA graphics modes are taken care of here, including all 16-color VGA graphics modes.
*/
this.updateScreenGraphicsEGA(addrBuffer, addrScreen, addrScreenLimit);
}
else {
/*
* Finally, all 256-color VGA modes are processed here.
*/
this.updateScreenGraphicsVGA(addrBuffer, addrScreen, addrScreenLimit);
}
};
/**
* updateScreenText(addrScreen, addrScreenLimit, iCell, nCells)
*
* @param addrScreen
* @param addrScreenLimit
* @param iCell
* @param nCells
*/
Video.prototype.updateScreenText = function(addrScreen, addrScreenLimit, iCell, nCells)
{
var addr, data, cUpdated = 0;
/*
* If MDA.MODE.BLINK_ENABLE is set and a cell's blink bit is set, then if (cBlinks & 0x2) != 0,
* we want the foreground element of the cell to be drawn; otherwise we don't. So every 16-bit
* data word we pull from the video buffer will be supplemented with our own special attribute bit
* (ATTRS.DRAW_FGND = 0x100) accordingly; and to simplify the drawing code, we will also mask the
* blink bit from the cell's attribute bits.
*
* If MDA.MODE.BLINK_ENABLE is clear, then we always set ATTRS.DRAW_FGND and never mask the blink
* bit in a cell's attributes bits, since it's actually an intensity bit in that case.
*/
this.cBlinkVisible = 0;
var dataBlink = 0;
var dataDraw = (Video.ATTRS.DRAW_FGND << 8);
var dataMask = 0xfffff;
var fBlinkEnable = (this.cardActive.regMode & Card.MDA.MODE.BLINK_ENABLE);
if (this.nCard >= Video.CARD.EGA) {
fBlinkEnable = (this.cardActive.regATCData[Card.ATC.MODE.INDX] & Card.ATC.MODE.BLINK_ENABLE);
}
/*
* Since iCell is always relative to addrScreen, we must make iCellCursor similarly relative,
* otherwise the cursor test below fails when the active video page is something other than page 0.
*/
var iCellCursor = this.iCellCursor - this.cardActive.offStartAddr;
if (fBlinkEnable) {
dataBlink = (Video.ATTRS.BGND_BLINK << 8);
dataMask &= ~dataBlink;
if (!(this.cBlinks & 0x2)) dataMask &= ~dataDraw;
}
addr = addrScreen + (iCell << 1);
while (addr < addrScreenLimit && iCell < nCells) {
data = this.bus.getShortDirect(addr);
data |= dataDraw;
if (data & dataBlink) {
this.cBlinkVisible++;
data &= dataMask;
}
if (iCell == iCellCursor) {
data |= ((this.cBlinks & 0x1)? (Video.ATTRS.DRAW_CURSOR << 8) : 0);
}
this.assert(iCell < this.aCellCache.length);
if (!this.fCellCacheValid || data !== this.aCellCache[iCell]) {
var col = iCell % this.nCols;
var row = (iCell / this.nCols)|0;
this.updateChar(col, row, data, this.contextScreenBuffer);
this.aCellCache[iCell] = data;
cUpdated++;
}
addr += 2;
iCell++;
}
this.fCellCacheValid = true;
if (cUpdated && this.contextScreenBuffer) {
this.contextScreen.drawImage(this.canvasScreenBuffer, 0, 0, this.cxBuffer, this.cyBuffer, this.xScreenOffset, this.yScreenOffset, this.cxScreenOffset, this.cyScreenOffset);
}
};
/**
* updateScreenGraphicsCGA(addrScreen, addrScreenLimit)
*
* @param addrScreen
* @param addrScreenLimit
*/
Video.prototype.updateScreenGraphicsCGA = function(addrScreen, addrScreenLimit)
{
var addr, data;
/*
* This is the CGA graphics-mode update case, where cells are pixels spread across two halves of the buffer.
*/
addr = addrScreen;
this.cBlinkVisible = 0;
var iCell = 0, nPixelsPerCell = this.nCellsPerWord;
var wPixelMask = (nPixelsPerCell == 16? 0x10000 : 0x30000);
var nPixelShift = (nPixelsPerCell == 16? 1 : 2);
var aPixelColors = this.getCardColors(nPixelShift);
var x = 0, y = 0;
var xDirty = this.nCols, xMaxDirty = 0, yDirty = this.nRows, yMaxDirty = 0;
while (addr < addrScreenLimit) {
data = this.bus.getShortDirect(addr);
this.assert(iCell < this.aCellCache.length);
if (this.fCellCacheValid && data === this.aCellCache[iCell]) {
x += nPixelsPerCell;
} else {
this.aCellCache[iCell] = data;
var wPixels = (data >> 8) | ((data & 0xff) << 8);
var wMask = wPixelMask, nShift = 16;
if (x < xDirty) xDirty = x;
for (var iPixel = 0; iPixel < nPixelsPerCell; iPixel++) {
var bPixel = (wPixels & (wMask >>= nPixelShift)) >> (nShift -= nPixelShift);
this.setPixel(this.imageScreenBuffer, x++, y, aPixelColors[bPixel]);
}
if (x > xMaxDirty) xMaxDirty = x;
if (y < yDirty) yDirty = y;
if (y >= yMaxDirty) yMaxDirty = y + 1;
}
addr += 2;
iCell++;
if (x >= this.nCols) {
x = 0;
y += 2;
if (y > this.nRows)
break;
if (y == this.nRows) {
y = 1;
addr = addrScreen + this.cbSplit;
}
}
}
this.fCellCacheValid = true;
/*
* Instead of blasting the ENTIRE imageScreenBuffer into contextScreenBuffer, and then blasting the ENTIRE
* canvasScreenBuffer onto contextScreen, even for the smallest change, let's try to be a bit smarter about
* the update (well, to the extent that the canvas APIs permit).
*/
if (xDirty < this.nCols) {
var cxDirty = xMaxDirty - xDirty;
var cyDirty = yMaxDirty - yDirty;
// this.contextScreenBuffer.putImageData(this.imageScreenBuffer, 0, 0);
this.contextScreenBuffer.putImageData(this.imageScreenBuffer, 0, 0, xDirty, yDirty, cxDirty, cyDirty);
/*
* While ideally I would draw only the dirty portion of canvasScreenBuffer, there usually isn't a 1-1 pixel mapping
* between canvasScreenBuffer and contextScreen. In fact, the WHOLE POINT of the canvasScreenBuffer is to leverage
* drawImage()'s scaling ability; for example, a CGA graphics mode might be 640x200, whereas the canvas representing
* the screen might be 960x400. In those situations, if we draw interior rectangles, we often end up with subpixel
* artifacts along the edges of those rectangles. So it appears I must continue to redraw the entire canvasScreenBuffer
* on every change.
*
var xScreen = (((xDirty * this.cxScreen) / this.nCols) | 0);
var yScreen = (((yDirty * this.cyScreen) / this.nRows) | 0);
var cxScreen = (((cxDirty * this.cxScreen) / this.nCols) | 0);
var cyScreen = (((cyDirty * this.cyScreen) / this.nRows) | 0);
this.contextScreen.drawImage(this.canvasScreenBuffer, xDirty, yDirty, cxDirty, cyDirty, xScreen, yScreen, cxScreen, cyScreen);
*/
this.contextScreen.drawImage(this.canvasScreenBuffer, 0, 0, this.nCols, this.nRows, 0, 0, this.cxScreen, this.cyScreen);
}
};
/**
* updateScreenGraphicsEGA(addrBuffer, addrScreen, addrScreenLimit)
*
* TODO: Add support for blinking graphics (ATC.MODE.BLINK_ENABLE)
*
* @param {number} addrBuffer
* @param {number} addrScreen
* @param {number} addrScreenLimit
*/
Video.prototype.updateScreenGraphicsEGA = function(addrBuffer, addrScreen, addrScreenLimit)
{
var addr, data;
addr = addrScreen;
this.cBlinkVisible = 0;
var iCell = 0;
var aPixelColors = this.getCardColors();
var adwMemory = this.cardActive.adwMemory;
var x = 0, y = 0;
var xDirty = this.nCols, xMaxDirty = 0, yDirty = this.nRows, yMaxDirty = 0;
var iPixelFirst = this.cardActive.regATCData[Card.ATC.HPAN.INDX] & Card.ATC.HPAN.SHIFT_LEFT;
/*
* TODO: What should happen if the card is programmed such that nColsLogical is LESS THAN nCols?
*/
var nRowAdjust = (this.nColsLogical > this.nCols? ((this.nColsLogical - this.nCols - iPixelFirst) >> 3) : 0);
while (addr < addrScreenLimit) {
var idw = addr++ - addrBuffer;
this.assert(idw >= 0 && idw < adwMemory.length);
data = adwMemory[idw];
/*
* Figure out how many visible pixels this data represents; usually 8, unless panning is being used.
*/
var iPixel, nPixels = 8;
if (iPixelFirst) {
/*
* Notice that we're not using the cell cache when panning is active, because the cached cell data no
* longer aligns with the data we're pulling out of the video buffer, and it's not clear that the effort
* to realign the data and make a valid cache comparison would save enough work to make it worthwhile.
*/
if (!x) {
data <<= iPixelFirst;
nPixels -= iPixelFirst;
/*
* This is as good a place as any to invalidate the cell cache when panning is active; this ensures
* we don't rely on stale cache contents once panning stops.
*/
this.fCellCacheValid = false;
} else {
iPixel = this.nCols - x;
if (nPixels > iPixel) nPixels = iPixel;
}
} else {
this.assert(iCell < this.aCellCache.length);
if (this.fCellCacheValid && data === this.aCellCache[iCell]) {
x += nPixels;
nPixels = 0;
} else {
this.aCellCache[iCell] = data;
}
iCell++;
}
if (nPixels) {
if (x < xDirty) xDirty = x;
for (iPixel = 0; iPixel < nPixels; iPixel++) {
/*
* 0x80808080 may LOOK like a 32-bit value, but it is not, because JavaScript treats it as a POSITIVE
* number, and therefore outside the normal 32-bit integer range; however, the AND operator guarantees
* that the result will be a 32-bit value, so it doesn't matter.
*/
var dwPixel = data & 0x80808080;
this.assert(Video.aEGADWToByte[dwPixel] !== undefined);
/*
* Since assertions don't fix problems (only catch them, and only in DEBUG builds), I'm also ensuring
* that bPixel will default to 0 if an undefined value ever slips through again.
*
* How did an undefined value slip through? We had (incorrectly) initialized entries in aEGADWToByte;
* for example, we used to set aEGADWToByte[0x80808080] instead of aEGADWToByte[0x80808080|0]. The
* former is a POSITIVE index that is outside the 32-bit integer range, whereas the latter is a NEGATIVE
* index, which is what this code requires.
*/
var bPixel = Video.aEGADWToByte[dwPixel] || 0;
this.setPixel(this.imageScreenBuffer, x++, y, aPixelColors[bPixel]);
data <<= 1;
}
if (x > xMaxDirty) xMaxDirty = x;
if (y < yDirty) yDirty = y;
if (y >= yMaxDirty) yMaxDirty = y + 1;
}
this.assert(x <= this.nCols);
if (x >= this.nCols) {
x = 0;
if (++y > this.nRows) break;
addr += nRowAdjust;
}
}
if (!iPixelFirst) this.fCellCacheValid = true;
/*
* For a fascinating discussion of the best way to update the screen canvas at this point, see updateScreenGraphicsCGA().
*/
if (xDirty < this.nCols) {
var cxDirty = xMaxDirty - xDirty;
var cyDirty = yMaxDirty - yDirty;
this.contextScreenBuffer.putImageData(this.imageScreenBuffer, 0, 0, xDirty, yDirty, cxDirty, cyDirty);
this.contextScreen.drawImage(this.canvasScreenBuffer, 0, 0, this.nCols, this.nRows, 0, 0, this.cxScreen, this.cyScreen);
}
};
/**
* updateScreenGraphicsVGA(addrBuffer, addrScreen, addrScreenLimit)
*
* This function name is a slight misnomer: updateScreenGraphicsEGA() takes care of all the 4bpp video modes
* (first introduced by the EGA and later expanded by the VGA), where each pixel's bits are spread across the 4
* planes, whereas this function takes care of just the 8bpp video modes introduced by the VGA, such as mode 0x13
* (320x200x256), where each pixel's bits are contained within a single plane. This is essentially all 256-color
* modes (CHAIN4, "Mode X", etc), hence the hard-coded call to getCardColors(8).
*
* TODO: Add support for blinking graphics (ATC.MODE.BLINK_ENABLE)
*
* @param {number} addrBuffer
* @param {number} addrScreen
* @param {number} addrScreenLimit
*/
Video.prototype.updateScreenGraphicsVGA = function(addrBuffer, addrScreen, addrScreenLimit)
{
var addr, data;
addr = addrScreen;
this.cBlinkVisible = 0;
var iCell = 0;
var aPixelColors = this.getCardColors(8);
var adwMemory = this.cardActive.adwMemory;
var x = 0, y = 0;
var xDirty = this.nCols, xMaxDirty = 0, yDirty = this.nRows, yMaxDirty = 0;
var cbInc = (this.cardActive.regSEQData[Card.SEQ.MEMMODE.INDX] & Card.SEQ.MEMMODE.CHAIN4)? 4 : 1;
var iPixelFirst = this.cardActive.regATCData[Card.ATC.HPAN.INDX] & Card.ATC.HPAN.SHIFT_LEFT;
/*
* TODO: What should happen if the card is programmed such that nColsLogical is LESS THAN nCols?
*/
var nRowAdjust = (this.nColsLogical > this.nCols? ((this.nColsLogical - this.nCols - iPixelFirst) >> 3) : 0);
while (addr < addrScreenLimit) {
var idw = addr - addrBuffer;
this.assert(idw >= 0 && idw < adwMemory.length);
data = adwMemory[idw];
/*
* Figure out how many visible pixels this data represents; usually 4, unless panning is being used.
*/
var iPixel, nPixels = 4;
if (iPixelFirst) {
/*
* TODO: Implement support for 8bpp panning
*/
} else {
this.assert(iCell < this.aCellCache.length);
if (this.fCellCacheValid && data === this.aCellCache[iCell]) {
x += nPixels;
nPixels = 0;
} else {
this.aCellCache[iCell] = data;
}
iCell++;
}
if (nPixels) {
if (x < xDirty) xDirty = x;
for (iPixel = 0; iPixel < nPixels; iPixel++) {
this.setPixel(this.imageScreenBuffer, x++, y, aPixelColors[data & 0xff]);
data >>= 8;
}
if (x > xMaxDirty) xMaxDirty = x;
if (y < yDirty) yDirty = y;
if (y >= yMaxDirty) yMaxDirty = y + 1;
}
this.assert(x <= this.nCols);
addr += cbInc;
if (x >= this.nCols) {
x = 0;
if (++y > this.nRows) break;
addr += nRowAdjust;
}
}
if (!iPixelFirst) this.fCellCacheValid = true;
/*
* For a fascinating discussion of the best way to update the screen canvas at this point, see updateScreenGraphicsCGA().
*/
if (xDirty < this.nCols) {
var cxDirty = xMaxDirty - xDirty;
var cyDirty = yMaxDirty - yDirty;
this.contextScreenBuffer.putImageData(this.imageScreenBuffer, 0, 0, xDirty, yDirty, cxDirty, cyDirty);
this.contextScreen.drawImage(this.canvasScreenBuffer, 0, 0, this.nCols, this.nRows, 0, 0, this.cxScreen, this.cyScreen);
}
};
/**
* getRetraceBits(card)
*
* This returns a byte value with two bits set or clear as appropriate: RETRACE and VRETRACE.
*
* @this {Video}
* @param {Object} card
* @return {number}
*/
Video.prototype.getRetraceBits = function(card)
{
var b = 0;
/*
* NOTE: The CGA bits CGA.STATUS.RETRACE (0x01) and CGA.STATUS.VRETRACE (0x08) match the EGA definitions,
* and they also correspond to the MDA bits MDA.STATUS.HDRIVE (0x01) and MDA.STATUS.BWVIDEO (0x08); I'm not sure
* why the MDA uses different designations, but the bits appear to serve the same purpose.
*
* TODO: Decide whether this more faithful emulation of the retrace bits should be extended to the MDA/CGA, too;
* doing so might slow down the BIOS scroll code a bit, though.
*
* TODO: Verify that when a saved machine state is restored, both the CPU's cycle count AND the card's nInitCycles
* are properly restored. It's probably not a big deal, but details like that bother me.
*/
var nCycles = this.cpu.getCycles();
var nElapsedCycles = nCycles - card.nInitCycles;
if (nElapsedCycles < 0) { // perhaps the CPU decided to reset its cycle count?
card.nInitCycles = nElapsedCycles;
nElapsedCycles = -nElapsedCycles|0;
}
var nCyclesHorzRemain = nElapsedCycles % card.nCyclesHorzPeriod;
if (nCyclesHorzRemain > card.nCyclesHorzActive) b |= Card.CGA.STATUS.RETRACE;
var nCyclesVertRemain = nElapsedCycles % card.nCyclesVertPeriod;
if (nCyclesVertRemain > card.nCyclesVertActive) b |= Card.CGA.STATUS.VRETRACE | Card.CGA.STATUS.RETRACE;
/*
* Some callers also want to know how many vertical retrace periods have occurred since the last time they checked,
* so we compute that now.
*/
card.nVertPeriods = (nElapsedCycles / card.nCyclesVertPeriod)|0;
/*
* The number of CPU cycles that remain in the current vertical period is all we USED to keep track of, since
* keeping track of the total number of cycles since the card was initialized can result in an extremely large
* delta after a while.
*
* card.nInitCycles = nCycles - nCyclesVertRemain;
*
* HOWEVER, now that we're calling getRetraceBits() more frequently (ie, for internal retrace checks), resetting
* nInitCycles in this fashion alters the horizontal period too much, causing grief in ROM BIOS code that requires
* strict horizontal retrace times. Also, the CPU reserves the right to occasionally reset its own cycle count.
* A final complication is that nVertPeriods would no longer be accurate if we constantly reduced nInitCycles.
*
* None of those are insurmountable problems, but the simple solution is to never reduce nInitCycles (well, except
* when forced to by a reduction in the CPU's cycle count).
*/
return b;
};
/**
* inMDAIndx(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3B4)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number|undefined}
*/
Video.prototype.inMDAIndx = function(port, addrFrom)
{
return this.inCRTCIndx(this.cardMono, port, addrFrom);
};
/**
* outMDAIndx(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3B4)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outMDAIndx = function(port, bOut, addrFrom)
{
this.outCRTCIndx(this.cardMono, port, bOut, addrFrom);
};
/**
* inMDAData(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3B5)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number|undefined}
*/
Video.prototype.inMDAData = function(port, addrFrom)
{
return this.inCRTCData(this.cardMono, port, addrFrom);
};
/**
* outMDAData(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3B5)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outMDAData = function(port, bOut, addrFrom)
{
this.outCRTCData(this.cardMono, port, bOut, addrFrom);
};
/**
* inMDAMode(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3B8)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inMDAMode = function(port, addrFrom)
{
return this.inCardMode(this.cardMono, addrFrom);
};
/**
* outMDAMode(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3B8)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outMDAMode = function(port, bOut, addrFrom)
{
this.outCardMode(this.cardMono, bOut, addrFrom);
};
/**
* inMDAStatus(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3BA)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inMDAStatus = function(port, addrFrom)
{
return this.inCardStatus(this.cardMono, addrFrom);
};
/**
* outFeat(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3BA or 0x3DA)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*
* NOTE: While this port also existed on the MDA and CGA, it existed only as an INPUT port, not an OUTPUT port.
*/
Video.prototype.outFeat = function(port, bOut, addrFrom)
{
this.cardEGA.regFeat = (this.cardEGA.regFeat & ~Card.FEAT_CTRL.BITS) | (bOut & Card.FEAT_CTRL.BITS);
this.printMessageIO(port, bOut, addrFrom, "FEAT");
};
/**
* inATCIndx(port, addrFrom)
*
* Technically, port 0x3C0 is readable only on a VGA, but we allow reads on an EGA as well,
* primarily for debugging purposes. Moreover, ATC port reads do NOT toggle the ATC address/data
* flip-flop; only writes have that effect.
*
* @this {Video}
* @param {number} port (0x3C0)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inATCIndx = function(port, addrFrom)
{
var b = this.cardEGA.regATCIndx;
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.ATC.PORT, null, addrFrom, "ATC.INDX", b);
}
return b;
};
/**
* inATCData(port, addrFrom)
*
* Technically, port 0x3C0 is readable only on a VGA, but we allow reads on an EGA as well,
* primarily for debugging purposes. Moreover, ATC port reads do NOT toggle the ATC address/data
* flip-flop; only writes have that effect.
*
* @this {Video}
* @param {number} port (0x3C1)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inATCData = function(port, addrFrom)
{
var b = this.cardEGA.regATCData[this.cardEGA.regATCIndx & Card.ATC.INDX_MASK];
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.ATC.PORT, null, addrFrom, "ATC." + this.cardEGA.asATCRegs[this.cardEGA.regATCIndx & Card.ATC.INDX_MASK], b);
}
return b;
};
/**
* outATC(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C0)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outATC = function(port, bOut, addrFrom)
{
var card = this.cardEGA;
var fPalEnabled = (card.regATCIndx & Card.ATC.INDX_PAL_ENABLE);
if (!card.fATCData) {
card.regATCIndx = bOut;
this.printMessageIO(port, bOut, addrFrom, "ATC.INDX");
card.fATCData = true;
if ((bOut & Card.ATC.INDX_PAL_ENABLE) && !fPalEnabled) {
if (!this.buildFonts(true)) {
if (DEBUG && (!addrFrom || this.messageEnabled())) {
this.printMessage("outATC(" + str.toHexByte(bOut) + "): no font changes required");
}
} else {
if (DEBUG && (!addrFrom || this.messageEnabled())) {
this.printMessage("outATC(" + str.toHexByte(bOut) + "): redraw screen for font changes");
}
this.updateScreen(true);
}
}
else {
/*
* TODO: We might want a screen blanking function, suitable for any mode, when INDX_PAL_ENABLE is cleared.
* powerDown() might like to use such a function, too. updateScreen() already disables any further screen
* updates while INDX_PAL_ENABLE is clear (except when fForce is true), but that's all we currently do.
*
* if (!(bOut & Card.ATC.INDX_PAL_ENABLE) && fPalEnabled) this.blankScreen();
*
* However, there also needs to be a delay, because when the IBM VGA BIOS changes the mode, it updates
* the ATC palette registers in such a way that INDX_PAL_ENABLE is constantly toggled; here's one iteration:
*
* C000:2B39 EC IN AL,DX
* C000:2B3A B2C0 MOV DL,C0
* C000:2B3C 8BC3 MOV AX,BX
* C000:2B3E 86C4 XCHG AL,AH
* C000:2B40 EE OUT DX,AL <-- this ATC index value does NOT contain 0x20
* C000:2B41 86C4 XCHG AL,AH
* C000:2B43 EE OUT DX,AL
* C000:2B44 B020 MOV AL,20
* C000:2B46 EE OUT DX,AL <-- this ATC index value obviously DOES contain 0x20
*
* I'm not sure there are any situations where deliberately flickering the screen is a good thing -- unless
* someone REALLY wants to recreate the ugly flickering scroll of a CGA...?
*/
}
/*
* HACK: offStartAddr is supposed to be "latched" ONLY at the start of every VRETRACE interval, but
* other "triggers" are helpful; see updateScreen() for details.
*
* PARANOIA: Don't call invalidateCache() unless the start address we just "latched" actually changed.
*/
var offStartAddr = ((card.regCRTData[Card.CRTC.START_ADDR_HI] << 8) + card.regCRTData[Card.CRTC.START_ADDR_LO])|0;
if (card.offStartAddr != offStartAddr) {
card.offStartAddr = offStartAddr;
this.invalidateCache();
}
card.nVertPeriodsStartAddr = 0;
} else {
card.fATCData = false;
var iReg = card.regATCIndx & Card.ATC.INDX_MASK;
if (iReg >= Card.ATC.PALETTE_REGS || !fPalEnabled) {
if (Video.TRAPALL || card.regATCData[iReg] !== bOut) {
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(port, bOut, addrFrom, "ATC." + card.asATCRegs[iReg]);
}
card.regATCData[iReg] = bOut;
this.invalidateCache(false);
}
}
}
};
/**
* inStatus0(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C2)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inStatus0 = function(port, addrFrom)
{
var bSWBit = 0;
if (this.nCard == Video.CARD.EGA) {
var iBit = 3 - ((this.cardEGA.regMisc & Card.MISC.CLOCK_SELECT) >> 2); // this is the desired SW # (0-3)
bSWBit = (this.bEGASwitches & (1 << iBit)) << (Card.STATUS0.SWSENSE_SHIFT - iBit);
} else {
/*
* The IBM VGA ROM expects the SWSENSE bit to change according to how the DAC is programmed.
*
* At C000:0391, the ROM selects the following array at 0x0454:
*
* db 0x12,0x12,0x12,0x10
*
* and writes the first 3 bytes to DAC register #0, and then compares SWSENSE to the 4th byte (0x10).
*
* If the 4th byte matches, then the ROM clears the BIOS "monochrome monitor" bit, and does the same
* thing again with 5 more arrays, expecting the 4th byte in all 5 arrays to match SWSENSE, and being
* very unhappy if they don't:
*
* db 0x14,0x14,0x14,0x10
* db 0x2D,0x14,0x14,0x00
* db 0x14,0x2D,0x14,0x00
* db 0x14,0x14,0x2D,0x00
* db 0x2D,0x2D,0x2D,0x00
*
* I ensure much happiness by setting SWSENSE unless any of the three 6-bit DAC values contain 0x2D.
*
* This hard-coded behavior assumes a color monitor. If you really want to simulate a monochrome monitor,
* then the 1st array (above) must mismatch, and a different set of arrays must all match:
*
* db 0x04,0x12,0x04,0x10
* db 0x1E,0x12,0x04,0x00
* db 0x04,0x2D,0x04,0x00
* db 0x04,0x16,0x15,0x00
* db 0x00,0x00,0x00,0x10
*
* In other words, for a monochrome monitor, set SWSENSE only when DAC register #0 matches the first and last
* sets of values.
*/
var dwDAC = this.cardEGA.regDACData[0];
if ((dwDAC & 0x3f) != 0x2d && (dwDAC & (0x3f << 6)) != (0x2d << 6) && (dwDAC & (0x3f << 12)) != (0x2d << 12)) {
bSWBit |= Card.STATUS0.SWSENSE;
}
}
var b = ((this.cardEGA.regStatus0 & ~Card.STATUS0.SWSENSE) | bSWBit);
/*
* TODO: Figure out where Card.STATUS0.FEAT bits should come from....
*/
this.cardEGA.regStatus0 = b;
this.printMessageIO(Card.STATUS0.PORT, null, addrFrom, "STATUS0", b);
return b;
};
/**
* @this {Video}
* @param {number} port (0x3C2)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outMisc = function(port, bOut, addrFrom)
{
this.cardEGA.regMisc = bOut;
this.enableEGA();
this.printMessageIO(Card.MISC.PORT_WRITE, bOut, addrFrom, "MISC");
};
/**
* inVGAEnable(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C3)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inVGAEnable = function(port, addrFrom)
{
var b = this.cardEGA.regVGAEnable;
this.printMessageIO(Card.VGA_ENABLE.PORT, null, addrFrom, "VGA_ENABLE", b);
return b;
};
/**
* outVGAEnable(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C3)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outVGAEnable = function(port, bOut, addrFrom)
{
this.cardEGA.regVGAEnable = bOut;
this.printMessageIO(Card.VGA_ENABLE.PORT, bOut, addrFrom, "VGA_ENABLE");
};
/**
* inSEQIndx(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C4)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inSEQIndx = function(port, addrFrom)
{
var b = this.cardEGA.regSEQIndx;
this.printMessageIO(Card.SEQ.INDX.PORT, null, addrFrom, "SEQ.INDX", b);
return b;
};
/**
* outSEQIndx(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C4)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outSEQIndx = function(port, bOut, addrFrom)
{
this.cardEGA.regSEQIndx = bOut;
this.printMessageIO(Card.SEQ.INDX.PORT, bOut, addrFrom, "SEQ.INDX");
};
/**
* inSEQData(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C5)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inSEQData = function(port, addrFrom)
{
var b = this.cardEGA.regSEQData[this.cardEGA.regSEQIndx];
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.SEQ.DATA.PORT, null, addrFrom, "SEQ." + this.cardEGA.asSEQRegs[this.cardEGA.regSEQIndx], b);
}
return b;
};
/**
* outSEQData(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C5)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outSEQData = function(port, bOut, addrFrom)
{
if (Video.TRAPALL || this.cardEGA.regSEQData[this.cardEGA.regSEQIndx] !== bOut) {
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.SEQ.DATA.PORT, bOut, addrFrom, "SEQ." + this.cardEGA.asSEQRegs[this.cardEGA.regSEQIndx]);
}
this.cardEGA.regSEQData[this.cardEGA.regSEQIndx] = bOut;
}
switch(this.cardEGA.regSEQIndx) {
case Card.SEQ.MAPMASK.INDX:
this.cardEGA.nSeqMapMask = Video.aEGAByteToDW[bOut & Card.SEQ.MAPMASK.MAPS];
break;
case Card.SEQ.MEMMODE.INDX:
if (this.setCardAccess(this.getCardAccess())) {
/*
* When switching screens (via SysReq) on early revisions of OS/2 (eg, FOOTBALL), the screen would go
* blank; this appeared to be because when the card is reprogrammed, we first think the card is going into
* graphics mode, then we reverse course when it becomes clear that the card is going back into text mode,
* but unfortunately, at that precise moment, the Sequencer hasn't been fully reprogrammed, so when we're
* reading screen memory, we're getting back ZEROS for every odd byte (which are the text attribute bytes),
* so the screen is redrawn as black-on-black.
*
* My solution was to change setCardAccess() to indicate whether it actually altered the video buffer
* address and/or format, and if so, then force another screen update.
*
* TODO: This scenario does not seem unique; it suggests that we should generally force a screen update
* whenever the video buffer has undergone a significant change.
*
* UPDATE: This change was NOT sufficient to resolve the OS/2 screen-switching bug described above; in fact,
* it's apparently not even necessary, because the REAL problem was caused by PAGED blocks with stale
* physical video memory blocks; the solution was for the Bus addMemory() and removeMemory() functions to
* call the the CPU flushPageBlocks() function. With that change in place, the window now stays in sync
* with the buffer.
*
* However, calling updateScreen() here still seems like a good idea, and it shouldn't hurt performance,
* since we're doing it only when setCardAccess() indicates a change, so I'm leaving this addition in place.
*/
this.updateScreen(true);
}
break;
default:
break;
}
};
/**
* inDACMask(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C6)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inDACMask = function(port, addrFrom)
{
var b = this.cardEGA.regDACMask;
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.DAC.MASK.PORT, null, addrFrom, "DAC.MASK", b);
}
return b;
};
/**
* outDACMask(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C6)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outDACMask = function(port, bOut, addrFrom)
{
if (Video.TRAPALL || this.cardEGA.regDACMask !== bOut) {
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.DAC.MASK.PORT, bOut, addrFrom, "DAC.MASK");
}
this.cardEGA.regDACMask = bOut;
}
};
/**
* inDACState(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C7)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inDACState = function(port, addrFrom)
{
var b = this.cardEGA.regDACState;
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.DAC.STATE.PORT, null, addrFrom, "DAC.STATE", b);
}
return b;
};
/**
* outDACRead(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C7)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outDACRead = function(port, bOut, addrFrom)
{
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.DAC.ADDR.PORT_READ, bOut, addrFrom, "DAC.READ");
}
this.cardEGA.regDACAddr = bOut;
this.cardEGA.regDACState = Card.DAC.STATE.MODE_READ;
this.cardEGA.regDACShift = 0;
};
/**
* outDACWrite(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C8)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outDACWrite = function(port, bOut, addrFrom)
{
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.DAC.ADDR.PORT_WRITE, bOut, addrFrom, "DAC.WRITE");
}
this.cardEGA.regDACAddr = bOut;
this.cardEGA.regDACState = Card.DAC.STATE.MODE_WRITE;
this.cardEGA.regDACShift = 0;
};
/**
* inDACData(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C9)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inDACData = function(port, addrFrom)
{
var b = (this.cardEGA.regDACData[this.cardEGA.regDACAddr] >> this.cardEGA.regDACShift) & 0x3f;
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.DAC.DATA.PORT, null, addrFrom, "DAC.DATA[" + str.toHexByte(this.cardEGA.regDACAddr) + "][" + str.toHexByte(this.cardEGA.regDACShift) + "]", b);
}
this.cardEGA.regDACShift += 6;
if (this.cardEGA.regDACShift > 12) {
this.cardEGA.regDACShift = 0;
this.cardEGA.regDACAddr = (this.cardEGA.regDACAddr + 1) & (Card.DAC.TOTAL_REGS-1);
}
return b;
};
/**
* outDACData(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3C9)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outDACData = function(port, bOut, addrFrom)
{
var dw = this.cardEGA.regDACData[this.cardEGA.regDACAddr];
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.DAC.DATA.PORT, bOut, addrFrom, "DAC.DATA[" + str.toHexByte(this.cardEGA.regDACAddr) + "][" + str.toHexByte(this.cardEGA.regDACShift) + "]");
}
var dwNew = (dw & ~(0x3f << this.cardEGA.regDACShift)) | ((bOut & 0x3f) << this.cardEGA.regDACShift);
if (dw !== dwNew) {
this.cardEGA.regDACData[this.cardEGA.regDACAddr] = dwNew;
this.invalidateCache(false);
}
this.cardEGA.regDACShift += 6;
if (this.cardEGA.regDACShift > 12) {
this.cardEGA.regDACShift = 0;
this.cardEGA.regDACAddr = (this.cardEGA.regDACAddr + 1) & (Card.DAC.TOTAL_REGS-1);
}
};
/**
* inVGAFeat(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3CA)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inVGAFeat = function(port, addrFrom)
{
var b = this.cardEGA.regFeat;
this.printMessageIO(Card.FEAT_CTRL.PORT_READ, null, addrFrom, "FEAT", b);
return b;
};
/**
* outGRCPos2(port, bOut, addrFrom)
*
* "The EGA was originally implemented by IBM using two Graphics Controller Chips. This register is used to program
* the Graphics #2 chip. See the Graphics #1 Position Register for details."
*
* "A one should be loaded into this location to map host data bus bits 2 and 3 to display planes 2 and 3, respectively."
*
* @this {Video}
* @param {number} port (0x3CA)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outGRCPos2 = function(port, bOut, addrFrom)
{
this.cardEGA.regGRCPos2 = bOut;
this.printMessageIO(Card.GRC.POS2_PORT, bOut, addrFrom, "GRC2");
};
/**
* inVGAMisc(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3CC)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inVGAMisc = function(port, addrFrom)
{
var b = this.cardEGA.regMisc;
this.printMessageIO(Card.MISC.PORT_READ, null, addrFrom, "MISC", b);
return b;
};
/**
* outGRCPos1(port, bOut, addrFrom)
*
* "The EGA was originally implemented by IBM using two Graphics Controller Chips. It was necessary to program
* each to respond to a different set of two consecutive bits of the 8-bit host data bus. In the IBM EGA implementation,
* a 0 must be loaded into this register. In the VGA, there is no analogous register."
*
* "A zero should be loaded into this location to map host data bus bits 0 and 1 to display planes 0 and 1 respectively."
*
* Note that this register was not readable on the EGA, and when the VGA came along, reads of this port read the Misc reg.
*
* @this {Video}
* @param {number} port (0x3CC)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outGRCPos1 = function(port, bOut, addrFrom)
{
this.cardEGA.regGRCPos1 = bOut;
this.printMessageIO(Card.GRC.POS1_PORT, bOut, addrFrom, "GRC1");
};
/**
* inGRCIndx(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3CE)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inGRCIndx = function(port, addrFrom)
{
var b = this.cardEGA.regGRCIndx;
this.printMessageIO(Card.GRC.INDX.PORT, null, addrFrom, "GRC.INDX", b);
return b;
};
/**
* outGRCIndx(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3CE)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outGRCIndx = function(port, bOut, addrFrom)
{
this.cardEGA.regGRCIndx = bOut;
this.printMessageIO(Card.GRC.INDX.PORT, bOut, addrFrom, "GRC.INDX");
};
/**
* inGRCData(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3CF)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inGRCData = function(port, addrFrom)
{
var b = this.cardEGA.regGRCData[this.cardEGA.regGRCIndx];
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.GRC.DATA.PORT, null, addrFrom, "GRC." + this.cardEGA.asGRCRegs[this.cardEGA.regGRCIndx], b);
}
return b;
};
/**
* outGRCData(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3CF)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outGRCData = function(port, bOut, addrFrom)
{
if (Video.TRAPALL || this.cardEGA.regGRCData[this.cardEGA.regGRCIndx] !== bOut) {
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(Card.GRC.DATA.PORT, bOut, addrFrom, "GRC." + this.cardEGA.asGRCRegs[this.cardEGA.regGRCIndx]);
}
this.cardEGA.regGRCData[this.cardEGA.regGRCIndx] = bOut;
}
switch(this.cardEGA.regGRCIndx) {
case Card.GRC.SRESET.INDX:
this.cardEGA.nSetMapData = Video.aEGAByteToDW[bOut & 0xf];
this.cardEGA.nSetMapBits = this.cardEGA.nSetMapData & ~this.cardEGA.nSetMapMask;
break;
case Card.GRC.ESRESET.INDX:
this.cardEGA.nSetMapMask = ~Video.aEGAByteToDW[bOut & 0xf];
this.cardEGA.nSetMapBits = this.cardEGA.nSetMapData & ~this.cardEGA.nSetMapMask;
break;
case Card.GRC.COLORCMP.INDX:
this.cardEGA.nColorCompare = Video.aEGAByteToDW[bOut & 0xf] & (0x80808080|0);
break;
case Card.GRC.DATAROT.INDX:
case Card.GRC.MODE.INDX:
this.setCardAccess(this.getCardAccess());
break;
case Card.GRC.READMAP.INDX:
this.cardEGA.nReadMapShift = (bOut & Card.GRC.READMAP.NUM) << 3;
break;
case Card.GRC.MISC.INDX:
this.checkMode(false);
break;
case Card.GRC.COLORDC.INDX:
this.cardEGA.nColorDontCare = Video.aEGAByteToDW[bOut & 0xf] & (0x80808080|0);
break;
case Card.GRC.BITMASK.INDX:
this.cardEGA.nBitMapMask = bOut | (bOut << 8) | (bOut << 16) | (bOut << 24);
break;
default:
break;
}
};
/**
* inCGAIndx(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D4)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number|undefined}
*/
Video.prototype.inCGAIndx = function(port, addrFrom)
{
return this.inCRTCIndx(this.cardColor, port, addrFrom);
};
/**
* outCGAIndx(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D4)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outCGAIndx = function(port, bOut, addrFrom)
{
this.outCRTCIndx(this.cardColor, port, bOut, addrFrom);
};
/**
* inCGAData(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D5)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number|undefined}
*/
Video.prototype.inCGAData = function(port, addrFrom)
{
return this.inCRTCData(this.cardColor, port, addrFrom);
};
/**
* outCGAData(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D5)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outCGAData = function(port, bOut, addrFrom)
{
this.outCRTCData(this.cardColor, port, bOut, addrFrom);
};
/**
* inCGAMode(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D8)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inCGAMode = function(port, addrFrom)
{
return this.inCardMode(this.cardColor, addrFrom);
};
/**
* outCGAMode(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D8)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outCGAMode = function(port, bOut, addrFrom)
{
this.outCardMode(this.cardColor, bOut, addrFrom);
};
/**
* inCGAColor(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D9)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inCGAColor = function(port, addrFrom)
{
var b = this.cardColor.regColor;
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(port /* this.cardColor.port + 5 */, null, addrFrom, this.cardColor.type + ".COLOR", b);
}
return b;
};
/**
* outCGAColor(port, bOut, addrFrom)
*
* @this {Video}
* @param {number} port (0x3D9)
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outCGAColor = function(port, bOut, addrFrom)
{
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(port /* this.cardColor.port + 5 */, bOut, addrFrom, this.cardColor.type + ".COLOR");
}
if (this.cardColor.regColor !== bOut) {
this.cardColor.regColor = bOut;
this.invalidateCache(false);
}
};
/**
* inCGAStatus(port, addrFrom)
*
* @this {Video}
* @param {number} port (0x3DA)
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inCGAStatus = function(port, addrFrom)
{
return this.inCardStatus(this.cardColor, addrFrom);
};
/**
* inCRTCIndx(card, port, addrFrom)
*
* @this {Video}
* @param {Object} card
* @param {number} port
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number|undefined}
*/
Video.prototype.inCRTCIndx = function(card, port, addrFrom)
{
var b;
/*
* The IBM VGA ROM makes some hardware determinations based on how the CRTC controller responds when
* the IO_SELECT bit in the Miscellaneous Output Register is cleared; normally, that would mean ports
* 0x3B? are decoded and ports 0x3D? are ignored. We didn't used to bother ignoring them, but the
* VGA ROM's logic requires it, so now we also check fActive. However, we ignore only CTRC reads;
* we retain any writes in case that information proves useful later.
*
* Note that returning an undefined value now signals the Bus component to return whatever default value
* it prefers (normally 0xff).
*/
if (card.fActive) b = card.regCRTIndx;
this.printMessageIO(port, null, addrFrom, "CRTC.INDX", b);
return b;
};
/**
* outCRTCIndx(card, port, bOut, addrFrom)
*
* @this {Video}
* @param {Object} card
* @param {number} port
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outCRTCIndx = function(card, port, bOut, addrFrom)
{
card.regCRTPrev = card.regCRTIndx;
card.regCRTIndx = bOut & Card.CGA.CRTC.INDX.MASK;
this.printMessageIO(port /* card.port */, bOut, addrFrom, "CRTC.INDX");
};
/**
* inCRTCData(card, port, addrFrom)
*
* @this {Video}
* @param {Object} card
* @param {number} port
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number|undefined}
*/
Video.prototype.inCRTCData = function(card, port, addrFrom)
{
var b;
/*
* The IBM VGA ROM makes some hardware determinations based on how the CRTC controller responds when
* the IO_SELECT bit in the Miscellaneous Output Register is cleared; normally, that would mean ports
* 0x3B? are decoded and ports 0x3D? are ignored. We didn't used to bother ignoring them, but the
* VGA ROM's logic requires it, so now we also check fActive. However, we ignore only CTRC reads;
* we retain any writes in case that information proves useful later.
*
* Note that returning an undefined value now signals the Bus component to return whatever default value
* it prefers (normally 0xff).
*/
if (card.fActive && card.regCRTIndx < card.nCRTCRegs) b = card.regCRTData[card.regCRTIndx];
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(port /* card.port + 1 */, null, addrFrom, "CRTC." + card.asCRTCRegs[card.regCRTIndx], b);
}
return b;
};
/**
* outCRTCData(card, port, bOut, addrFrom)
*
* @this {Video}
* @param {Object} card
* @param {number} port
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outCRTCData = function(card, port, bOut, addrFrom)
{
if (card.regCRTIndx < card.nCRTCRegs) {
if (Video.TRAPALL || card.regCRTData[card.regCRTIndx] !== bOut) {
if (!addrFrom || this.messageEnabled()) {
this.printMessageIO(port /* card.port + 1 */, bOut, addrFrom, "CRTC." + card.asCRTCRegs[card.regCRTIndx]);
}
card.regCRTData[card.regCRTIndx] = bOut;
}
if (card.regCRTIndx == Card.CRTC.START_ADDR_HI || card.regCRTIndx == Card.CRTC.START_ADDR_LO) {
/*
* HACK: offStartAddr is supposed to be "latched" ONLY at the start of every VRETRACE interval,
* but the best we can currently do is latch it during retrace; beyond that, all we can do is snap
* the vertical period count and latch it later, in updateScreen(), once the count has advanced.
*/
if (this.getRetraceBits(card) & Card.CGA.STATUS.RETRACE) {
/*
* PARANOIA: Don't call invalidateCache() unless the address we're about to "latch" actually changed.
*/
var offStartAddr = ((card.regCRTData[Card.CRTC.START_ADDR_HI] << 8) + card.regCRTData[Card.CRTC.START_ADDR_LO])|0;
if (card.offStartAddr !== offStartAddr) {
card.offStartAddr = offStartAddr;
this.invalidateCache();
}
} else if (!card.nVertPeriodsStartAddr) {
card.nVertPeriodsStartAddr = card.nVertPeriods;
}
}
/*
* During mode changes on the EGA, all the CRTC regs are typically programmed in sequence,
* and if that's all that's happening with Card.CRTC.MAX_SCAN.INDX, then we don't want to treat
* it special; let the mode change be detected normally (eg, when the GRC regs are written later).
*
* On the other hand, if this was an out-of-sequence write to Card.CRTC.MAX_SCAN.INDX, then
* yes, we want to force setMode() to call setDimensions(), which is key to setting the proper
* number of screen rows.
*
* The second part of the check is required to promptly detect a switch to "Mode X"; if we assume
* that anyone switching to "Mode X" will first switch to mode 0x13, then it's a given that they
* must reprogram the VDISP_END register, and that they will probably change it from 0x8F to 0xDF.
*
* Originally, I wasn't going to check specifically for 0xDF, to help catch other "Mode X" variations,
* but if I don't, then some spurious mode changes are triggered (eg, when Windows 1.0 switches from
* CGA graphics mode 0x06 to an EGA graphics mode).
*/
if (card.regCRTIndx == Card.CRTC.MAX_SCAN.INDX && card.regCRTPrev != Card.CRTC.MAX_SCAN.INDX-1 || card.regCRTIndx == Card.CRTC.EGA.VDISP_END && bOut == 0xDF) {
this.checkMode(true);
}
this.checkCursor();
} else {
if (DEBUG && (!addrFrom || this.messageEnabled())) {
this.printMessage("outCRTCData(): ignoring unexpected write to CRTC[" + str.toHexByte(card.regCRTIndx) + "]: " + str.toHexByte(bOut));
}
}
};
/**
* inCardMode(card, addrFrom)
*
* @this {Video}
* @param {Object} card
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inCardMode = function(card, addrFrom)
{
var b = card.regMode;
this.printMessageIO(card.port + 4, null, addrFrom, "MODE", b);
return b;
};
/**
* outCardMode(card, bOut, addrFrom)
*
* @this {Video}
* @param {Object} card
* @param {number} bOut
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
*/
Video.prototype.outCardMode = function(card, bOut, addrFrom)
{
this.printMessageIO(card.port + 4, bOut, addrFrom, "MODE");
card.regMode = bOut;
this.checkMode(false);
};
/**
* inCardStatus(card, addrFrom)
*
* On an EGA, this register is called "Status Register One" (0x3BA/0x3DA aka STATUS1), to distinguish it from
* "Status Register Zero" (0x3C2 aka STATUS0). One of the side-effects of reading STATUS1 is that it resets the
* ATC address/data flip-flop to "address" mode, which we emulate by setting cardEGA.fATCData to false, indicating
* that the ATC is not in "data" mode.
*
* @this {Video}
* @param {Object} card
* @param {number} [addrFrom] (not defined whenever the Debugger tries to read the specified port)
* @return {number}
*/
Video.prototype.inCardStatus = function(card, addrFrom)
{
var b = this.getRetraceBits(card);
if (card === this.cardEGA) {
/*
* STATUS1 diagnostic bits 5 and 4 are set according to the Card.ATC.PLANES.MUX bits:
*
* MUX Bit 5 Bit 4
* --- ---- ----
* 00: Red Blue
* 01: SecBlue Green
* 10: SecRed SecGreen
* 11: unused unused
*
* Depending on where we are in the horizontal and vertical periods (which can be inferred from the
* same elapsed cycle count that we used to simulate the retrace bits above), we could extract 4 bits
* from a corresponding region of the video buffer, "and" them with Card.ATC.PLANES.MASK, use
* that to index into the palette registers (cardEGA.regATCData), and use the resulting palette register
* bits to set these diagnostics bits. However, that's all rather tedious, and the process of extracting
* 4 appropriate bits from the video buffer varies depending on the video mode.
*
* Why are we even considering this? Because the EGA BIOS diagnostic code draws a bright reverse-video
* line of text blocks across the top of the screen, writes 0x3F to palette register 0x0f, and then
* monitors the STATUS1 diagnostic bits, waiting for those palette bits to show up. It turns out, however,
* that we can easily fool the EGA BIOS by simply toggling the diagnostic bits. So we take the easy way out.
*
* TODO: Faithful emulation of these bits is certainly doable, so consider doing that at some point.
*/
b |= ((card.regStatus & Card.STATUS1.DIAGNOSTIC) ^ Card.STATUS1.DIAGNOSTIC);
/*
* Last but not least, we must reset the EGA's ATC flip-flop whenever this register is read.
*/
card.fATCData = false;
}
else {
/*
* On the MDA/CGA, to satisfy ROM BIOS testing ("TEST.10"), it's sufficient to do a simple toggle of
* bits 0 and 3 on every read.
*
* Also, according to http://www.seasip.info/VintagePC/mda.html, on an MDA, bits 7-4 are always ON and
* bits 2-1 are always OFF, hence the "OR" of 0xf0.
*
* TODO: Decide whether to preserve the bits from getRetraceBits() on the MDA/CGA; we're continuing
* to do a simple toggle, partly on the theory that that may speed up the CGA BIOS scroll code a bit.
*/
b = (card.regStatus ^= (Card.CGA.STATUS.RETRACE | Card.CGA.STATUS.VRETRACE)) | 0xf0;
}
card.regStatus = b;
this.printMessageIO(card.port + 6, null, addrFrom, (card === this.cardEGA? "STATUS1" : "STATUS"), b);
return b;
};
/**
* dumpVideo(asArgs)
*
* @this {Video}
* @param {Array.<string>} asArgs
*/
Video.prototype.dumpVideo = function(asArgs)
{
if (DEBUGGER) {
if (!this.cardActive) {
this.dbg.println("no active video card");
return;
}
if (asArgs[0]) {
this.cardActive.dumpVideoBuffer(asArgs);
return;
}
this.dbg.println("BIOSMODE: " + str.toHexByte(this.nMode));
this.cardActive.dumpVideoCard();
}
};
/*
* Port input/output notification tables
*
* TODO: At one point, I'd added some "duplicate" entries for the MDA because, according to docs I'd read,
* MDA ports are decoded at multiple addresses. However, if this is important, then it should be verified
* and implemented consistently (eg, for CGA as well). For now, I'm decoding only the standard port addresses.
*
* For example, 0x3B5 is apparently also decoded at 0x3B1, 0x3B3, and 0x3B7, while 0x3B4 is also decoded at
* 0x3B0, 0x3B2, and 0x3B6.
*/
Video.aMDAPortInput = {
0x3B4: Video.prototype.inMDAIndx, // technically, not actually readable, but I want the Debugger to be able to read this
0x3B5: Video.prototype.inMDAData, // technically, the only CRTC Data registers that are readable are R14-R17
0x3B8: Video.prototype.inMDAMode, // technically, not actually readable, but I want the Debugger to be able to read this
0x3BA: Video.prototype.inMDAStatus
};
Video.aMDAPortOutput = {
0x3B4: Video.prototype.outMDAIndx,
0x3B5: Video.prototype.outMDAData,
0x3B8: Video.prototype.outMDAMode
};
Video.aCGAPortInput = {
0x3D4: Video.prototype.inCGAIndx, // technically, not actually readable, but I want the Debugger to be able to read this
0x3D5: Video.prototype.inCGAData, // technically, the only CRTC Data registers that are readable are R14-R17
0x3D8: Video.prototype.inCGAMode, // technically, not actually readable, but I want the Debugger to be able to read this
0x3D9: Video.prototype.inCGAColor, // technically, not actually readable, but I want the Debugger to be able to read this
0x3DA: Video.prototype.inCGAStatus
};
Video.aCGAPortOutput = {
0x3D4: Video.prototype.outCGAIndx,
0x3D5: Video.prototype.outCGAData,
0x3D8: Video.prototype.outCGAMode,
0x3D9: Video.prototype.outCGAColor
};
Video.aEGAPortInput = {
0x3C0: Video.prototype.inATCIndx, // technically, only readable on a VGA, but I want the Debugger to be able to read this, too
0x3C1: Video.prototype.inATCData, // technically, only readable on a VGA, but I want the Debugger to be able to read this, too
0x3C2: Video.prototype.inStatus0,
0x3C4: Video.prototype.inSEQIndx, // technically, only readable on a VGA, but I want the Debugger to be able to read this, too
0x3C5: Video.prototype.inSEQData, // technically, only readable on a VGA, but I want the Debugger to be able to read this, too
0x3CE: Video.prototype.inGRCIndx, // technically, only readable on a VGA, but I want the Debugger to be able to read this, too
0x3CF: Video.prototype.inGRCData // technically, only readable on a VGA, but I want the Debugger to be able to read this, too
};
/*
* WARNING: Unlike the EGA, a standard VGA does not support writes to 0x3C1, but it's easier for me to leave that
* ability in place, treating the VGA as a superset of the EGA as much as possible; will any code break because word
* OUTs to port 0x3C0 (and/or byte OUTs to port 0x3C1) actually work? Possibly, but highly unlikely.
*/
Video.aEGAPortOutput = {
0x3BA: Video.prototype.outFeat,
0x3C0: Video.prototype.outATC,
0x3C1: Video.prototype.outATC, // the EGA BIOS writes to this port (see C000:0416), implying that 0x3C0 and 0x3C1 both decode the same register
0x3C2: Video.prototype.outMisc, // FYI, since this overlaps with STATUS0.PORT, there's currently no way for the Debugger to read the Misc register
0x3C4: Video.prototype.outSEQIndx,
0x3C5: Video.prototype.outSEQData,
0x3CA: Video.prototype.outGRCPos2,
0x3CC: Video.prototype.outGRCPos1,
0x3CE: Video.prototype.outGRCIndx,
0x3CF: Video.prototype.outGRCData,
0x3DA: Video.prototype.outFeat
};
Video.aVGAPortInput = {
0x3C3: Video.prototype.inVGAEnable,
0x3C6: Video.prototype.inDACMask,
0x3C7: Video.prototype.inDACState,
0x3C9: Video.prototype.inDACData,
0x3CA: Video.prototype.inVGAFeat,
0x3CC: Video.prototype.inVGAMisc
};
Video.aVGAPortOutput = {
0x3C3: Video.prototype.outVGAEnable,
0x3C6: Video.prototype.outDACMask,
0x3C7: Video.prototype.outDACRead,
0x3C8: Video.prototype.outDACWrite,
0x3C9: Video.prototype.outDACData
};
/**
* Video.init()
*
* This function operates on every HTML element of class "video", extracting the
* JSON-encoded parameters for the Video constructor from the element's "data-value"
* attribute, invoking the constructor to create a Video component, and then binding
* any associated HTML controls to the new component.
*/
Video.init = function()
{
var aeVideo = Component.getElementsByClass(document, PCJSCLASS, "video");
for (var iVideo = 0; iVideo < aeVideo.length; iVideo++) {
var eVideo = aeVideo[iVideo];
var parmsVideo = Component.getComponentParms(eVideo);
var eCanvas = document.createElement("canvas");
if (eCanvas === undefined || !eCanvas.getContext) {
eVideo.innerHTML = "<br/>Missing &lt;canvas&gt; support. Please try a newer web browser.";
return;
}
eCanvas.setAttribute("class", "pcjs-canvas");
eCanvas.setAttribute("width", parmsVideo['screenWidth']);
eCanvas.setAttribute("height", parmsVideo['screenHeight']);
eCanvas.style.backgroundColor = parmsVideo['screenColor'];
/*
* The "contenteditable" attribute on a canvas element NOTICEABLY slows down canvas drawing on
* Safari as soon as you give the canvas focus (ie, click away from the canvas, and drawing speeds
* up; click on the canvas, and drawing slows down). So the "transparent textarea hack" that we
* once employed as only a work-around for Android devices is now our default.
*
* eCanvas.setAttribute("contenteditable", "true");
*
* HACK: A canvas style of "auto" provides for excellent responsive canvas scaling in EVERY browser
* except IE9/IE10, so I recalculate the appropriate CSS height every time the parent DIV is resized;
* IE11 works without this hack, so we take advantage of the fact that IE11 doesn't identify as "MSIE".
*
* The other reason it's good to keep this particular hack limited to IE9/IE10 is that most other
* browsers don't actually support an 'onresize' handler on anything but the window object.
*/
eCanvas.style.height = "auto";
if (web.getUserAgent().indexOf("MSIE") >= 0) {
eVideo.onresize = function(eParent, eChild, cx, cy) {
return function onResizeVideo() {
eChild.style.height = (((eParent.clientWidth * cy) / cx) | 0) + "px";
};
}(eVideo, eCanvas, parmsVideo['screenWidth'], parmsVideo['screenHeight']);
eVideo.onresize();
}
/*
* The following is a related hack that allows the user to force the screen to use a particular aspect
* ratio if an 'aspect' attribute or URL parameter is set. Initially, it's just for testing purposes
* until we figure out a better UI. And note that we use our web.onPageEvent() helper function to make
* sure we don't trample any other 'onresize' handler(s) attached to the window object.
*/
var aspect = +(parmsVideo['aspect'] || Component.parmsURL['aspect']);
/*
* No 'aspect' parameter yields NaN, which is falsey, and anything else must satisfy my arbitrary
* constraints of 0.3 <= aspect <= 3.33, to prevent any useless (or worse, browser-blowing) results.
*/
if (aspect && aspect >= 0.3 && aspect <= 3.33) {
web.onPageEvent('onresize', function(eParent, eChild, aspectRatio) {
return function onResizeWindow() {
/*
* Since aspectRatio is the target width/height, we have:
*
* eParent.clientWidth / eChild.style.height = aspectRatio
*
* which means that:
*
* eChild.style.height = eParent.clientWidth / aspectRatio
*
* so for example, if aspectRatio is 16:9, or 1.78, and clientWidth = 640,
* then the calculated height should approximately 360.
*/
eChild.style.height = ((eParent.clientWidth / aspectRatio)|0) + "px";
};
}(eVideo, eCanvas, aspect));
window['onresize']();
}
eVideo.appendChild(eCanvas);
/*
* HACK: Android-based browsers, like the Silk (Amazon) browser and Chrome for Android, don't honor the
* "contenteditable" attribute; that is, when the canvas receives focus, they don't activate the on-screen
* keyboard. So my fallback is to create a transparent textarea on top of the canvas.
*
* The parent DIV must have a style of "position:relative" (alternatively, a class of "pcjs-container"),
* so that we can position the textarea using absolute coordinates. Also, we don't want the textarea to be
* visible, but we must use "opacity:0" instead of "visibility:hidden", because the latter seems to prevent
* the element from receiving events. These styling requirements are taken care of in components.css
* (see references to the "pcjs-video-object" class).
*
* UPDATE: Unfortunately, Android keyboards like to compose whole words before transmitting any of the
* intervening characters; our textarea's keyDown/keyUp event handlers DO receive intervening key events,
* but their keyCode property is ZERO. Virtually the only usable key event we receive is the Enter key.
* Android users will have to use machines that include their own on-screen "soft keyboard", or use an
* external keyboard.
*
* The following attempt to use a password-enabled input field didn't work any better on Android. You could
* clearly see the overlaid semi-transparent input field, but none of the input characters were passed along,
* with the exception of the "Go" (Enter) key.
*
* var eInput = document.createElement("input");
* eInput.setAttribute("type", "password");
* eInput.setAttribute("style", "position:absolute; left:0; top:0; width:100%; height:100%; opacity:0.5");
* eVideo.appendChild(eInput);
*
* See this Chromium issue for more information: https://code.google.com/p/chromium/issues/detail?id=118639
*/
var eTextArea = document.createElement("textarea");
/*
* As noted in keyboard.js, the keyboard on an iOS device tends to pop up with the SHIFT key depressed,
* which is not the initial keyboard state that the Keyboard component expects, so hopefully turning off
* these "auto" attributes will help.
*/
if (web.isUserAgent("iOS")) {
eTextArea.setAttribute("autocapitalize", "off");
eTextArea.setAttribute("autocorrect", "off");
}
eVideo.appendChild(eTextArea);
/*
* Now we can create the Video object, record it, and wire it up to the associated document elements.
*/
var eContext = eCanvas.getContext("2d");
var video = new Video(parmsVideo, eCanvas, eContext, eTextArea /* || eInput */, eVideo);
/*
* Bind any video-specific controls (eg, the Refresh button). There are no essential controls, however;
* even the "Refresh" button is just a diagnostic tool, to ensure that the screen contents are up-to-date.
*/
Component.bindComponentControls(video, eVideo, PCJSCLASS);
}
};
/*
* Initialize every Video module on the page.
*/
web.onInit(Video.init);
if (NODE) module.exports = Video;
Reference in a new issue View git blame Copy permalink