Retro/pcjs
Watch
1
0
Fork
You've already forked pcjs
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Updated PC8080 and PDPjs to support RAM images, eliminating the need for the old "writable ROM" kludge; RAM images can include their own load and exec addresses as part of the JSON file, but the RAM component can provide explicit overrides (if no load address is specified either way, the default load address is the starting RAM address)

Browse source
This commit is contained in:
Jeff Parsons 2016-10-17 11:01:32 -07:00 • committed by Jeff Parsons
commit 980c2ac5ab
64 changed files with 1479 additions and 1154 deletions
Download patch file Download diff file Expand all files Collapse all files

146
modules/pc8080/lib/rom.js
View file

@ -34,7 +34,6 @@ if (NODE) {
var DumpAPI = require("../../shared/lib/dumpapi");
var Component = require("../../shared/lib/component");
var PC8080 = require("./defines");
var CPUDef8080 = require("./cpudef");
var Memory8080 = require("./memory");
}
@ -47,7 +46,6 @@ if (NODE) {
* size: amount of ROM, in bytes
* alias: physical alias address (null if none)
* file: name of ROM data file
* writable: true to make ROM writable (default is false)
*
* NOTE: The ROM data will not be copied into place until the Bus is ready (see initBus()) AND the
* ROM data file has finished loading (see doneLoad()).
@ -55,13 +53,6 @@ if (NODE) {
* Also, while the size parameter may seem redundant, I consider it useful to confirm that the ROM you received
* is the ROM you expected.
*
* Finally, while making ROM "writable" may seem a contradiction in terms, I want to be able to load selected
* binary files into memory purely for testing purposes, and the RAM component has no "file" option, so the
* simplest solution was to add the option to load binary files into memory as "writable" ROMs.
*
* Moreover, if a "writable" ROM is installed at addr 0x100, that triggers our "Fake CP/M" support, providing
* a quick-and-dirty means of loading simple CP/M test binaries. See addROM() for details.
*
* @constructor
* @extends Component
* @param {Object} parmsROM
@ -73,7 +64,7 @@ function ROM8080(parmsROM)
this.abROM = null;
this.addrROM = parmsROM['addr'];
this.sizeROM = parmsROM['size'];
this.fWritable = parmsROM['writable'];
/*
* The new 'alias' property can now be EITHER a single physical address (like 'addr') OR an array of
@ -112,30 +103,6 @@ function ROM8080(parmsROM)
Component.subclass(ROM8080);
ROM8080.CPM = {
BIOS: {
VECTOR: 0x0000
},
BDOS: {
VECTOR: 0x0005,
FUNC: { // function number (specified in regC)
RESET: 0x00,
CON_READ: 0x01, // output: A = L = ASCII character
CON_WRITE: 0x02, // input: E = ASCII character
AUX_READ: 0x03, // output: A = L = ASCII character
AUX_WRITE: 0x04, // input: E = ASCII character
PRN_WRITE: 0x05, // input: E = ASCII character
MEM_SIZE: 0x06, // output: base address of CCP (Console Command Processor), but which register? (perhaps moot if this was CP/M 1.3 only...)
CON_IO: 0x06, // input: E = ASCII character (or 0xFF to return ASCII character in A)
GET_IOBYTE: 0x07,
SET_IOBYTE: 0x08,
STR_WRITE: 0x09 // input: DE = address of string
}
}
};
ROM8080.CPM.VECTORS = [ROM8080.CPM.BIOS.VECTOR, ROM8080.CPM.BDOS.VECTOR];
/*
* NOTE: There's currently no need for this component to have a reset() function, since
* once the ROM data is loaded, it can't be changed, so there's nothing to reinitialize.
@ -350,31 +317,12 @@ ROM8080.prototype.copyROM = function()
*/
ROM8080.prototype.addROM = function(addr)
{
if (this.bus.addMemory(addr, this.sizeROM, this.fWritable? Memory8080.TYPE.RAM : Memory8080.TYPE.ROM)) {
if (this.bus.addMemory(addr, this.sizeROM, Memory8080.TYPE.ROM)) {
if (DEBUG) this.log("addROM(): copying ROM to " + str.toHexLong(addr) + " (" + str.toHexLong(this.abROM.length) + " bytes)");
var i;
for (i = 0; i < this.abROM.length; i++) {
this.bus.setByteDirect(addr + i, this.abROM[i]);
}
if (this.fWritable && addr == 0x100) {
/*
* Here's where we enable our "Fake CP/M" support, triggered by the user loading a "writable" ROM image
* at offset 0x100. Fake CP/M support works by installing HLT opcodes at well-known CP/M addresses
* (namely, 0x0000, which is the CP/M reset vector, and 0x0005, which is the CP/M system call vector) and
* then telling the CPU to call us whenever a HLT occurs, so we can check PC for one of these addresses.
*/
for (i = 0; i < ROM8080.CPM.VECTORS.length; i++) {
this.bus.setByteDirect(ROM8080.CPM.VECTORS[i], CPUDef8080.OPCODE.HLT);
}
this.cpu.addHaltCheck(function(rom) {
return function(addr) {
return rom.checkCPMVector(addr)
};
}(this));
this.cpu.setReset(addr);
}
return true;
}
/*
@ -383,96 +331,6 @@ ROM8080.prototype.addROM = function(addr)
return false;
};
/**
* checkCPMVector(addr)
*
* @this {ROM8080}
* @param {number} addr (of the HLT opcode)
* @return {boolean} true if special processing performed, false if not
*/
ROM8080.prototype.checkCPMVector = function(addr)
{
var i = ROM8080.CPM.VECTORS.indexOf(addr);
if (i >= 0) {
var fCPM = false;
var cpu = this.cpu;
var dbg = this.dbg;
if (addr == ROM8080.CPM.BDOS.VECTOR) {
fCPM = true;
switch(cpu.regC) {
case ROM8080.CPM.BDOS.FUNC.CON_WRITE:
this.writeCPMString(this.getCPMChar(cpu.regE));
break;
case ROM8080.CPM.BDOS.FUNC.STR_WRITE:
this.writeCPMString(this.getCPMString(cpu.getDE(), '$'));
break;
default:
fCPM = false;
break;
}
}
if (fCPM) {
CPUDef8080.opRET.call(cpu); // for recognized calls, automatically return
}
else if (dbg) {
this.println("\nCP/M vector " + str.toHexWord(addr));
cpu.setPC(addr); // this is purely for the Debugger's benefit, to show the HLT
dbg.stopCPU();
}
return true;
}
return false;
};
/**
* getCPMChar(ch)
*
* @this {ROM8080}
* @param {number} ch
* @return {string}
*/
ROM8080.prototype.getCPMChar = function(ch)
{
return String.fromCharCode(ch);
};
/**
* getCPMString(addr, chEnd)
*
* @this {ROM8080}
* @param {number} addr (of a string)
* @param {string|number} [chEnd] (terminating character, default is 0)
* @return {string}
*/
ROM8080.prototype.getCPMString = function(addr, chEnd)
{
var s = "";
var cchMax = 255;
var bEnd = chEnd && chEnd.length && chEnd.charCodeAt(0) || chEnd || 0;
while (cchMax--) {
var b = this.cpu.getByte(addr++);
if (b == bEnd) break;
s += String.fromCharCode(b);
}
return s;
};
/**
* writeCPMString(s)
*
* @this {ROM8080}
* @param {string} s
*/
ROM8080.prototype.writeCPMString = function(s)
{
s = s.replace(/\r/g, '');
if (this.controlPrint) {
this.controlPrint.value += s;
this.controlPrint.scrollTop = this.controlPrint.scrollHeight;
}
};
/**
* cloneROM(addr)
*