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

Fixed a regression in EGA/VGA video page calculations (introduced by the other recent paging-related fixes)

Browse source
This commit is contained in:
Jeff Parsons 2017-07-14 17:47:03 -07:00 • committed by Jeff Parsons
commit 1760ae4ff9
9 changed files with 1399 additions and 1369 deletions
Download patch file Download diff file Expand all files Collapse all files

52
modules/pcx86/lib/video.js
View file

@ -363,9 +363,11 @@ class Card {
this.regCRTData = data[5];
this.nCRTCRegs = Card.CRTC.TOTAL_REGS;
this.asCRTCRegs = DEBUGGER? Card.CRTC.REGS : [];
this.offStartAddr = ((this.regCRTData[Card.CRTC.STARTHIGH] & Card.CRTCMASKS[Card.CRTC.STARTHIGH]) << 8) | this.regCRTData[Card.CRTC.STARTLOW];
this.offStartAddr = this.regCRTData[Card.CRTC.STARTLOW] | (this.regCRTData[Card.CRTC.STARTHIGH] << 8);
this.addrMaskHigh = 0x3F; // card-specific mask for the high (bits 8 and up) of CRTC address registers
if (nCard >= Video.CARD.EGA) {
this.addrMaskHigh = 0xFF;
this.nCRTCRegs = Card.CRTC.EGA.TOTAL_REGS;
this.asCRTCRegs = DEBUGGER? Card.CRTC.EGA_REGS : [];
this.initEGA(data[6], nMonitorType);
@ -913,35 +915,35 @@ class Card {
{
var reg = this.regCRTData[iReg];
if (reg != null && this.nCard >= Video.CARD.EGA) {
var bOvrflowBit8 = 0, bOvrflowBit9 = 0, bMaxScanBit9 = 0;
var bOverflowBit8 = 0, bOverflowBit9 = 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;
bOverflowBit8 = Card.CRTC.EGA.OVERFLOW.VTOTAL_BIT8; // 0x01
if (this.nCard == Video.CARD.VGA) bOverflowBit9 = Card.CRTC.EGA.OVERFLOW.VTOTAL_BIT9;
break;
case Card.CRTC.EGA.CURSTART.INDX: // 0x0A
if (this.nCard == Video.CARD.EGA) bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.CURSTART_BIT8;
if (this.nCard == Video.CARD.EGA) bOverflowBit8 = Card.CRTC.EGA.OVERFLOW.CURSTART_BIT8;
break;
case Card.CRTC.EGA.VRSTART: // 0x10
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.VRSTART_BIT8; // 0x04
if (this.nCard == Video.CARD.VGA) bOvrflowBit9 = Card.CRTC.EGA.OVERFLOW.VRSTART_BIT9;
bOverflowBit8 = Card.CRTC.EGA.OVERFLOW.VRSTART_BIT8; // 0x04
if (this.nCard == Video.CARD.VGA) bOverflowBit9 = Card.CRTC.EGA.OVERFLOW.VRSTART_BIT9;
break;
case Card.CRTC.EGA.VDEND: // 0x12
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.VDEND_BIT8; // 0x02
if (this.nCard == Video.CARD.VGA) bOvrflowBit9 = Card.CRTC.EGA.OVERFLOW.VDEND_BIT9;
bOverflowBit8 = Card.CRTC.EGA.OVERFLOW.VDEND_BIT8; // 0x02
if (this.nCard == Video.CARD.VGA) bOverflowBit9 = Card.CRTC.EGA.OVERFLOW.VDEND_BIT9;
break;
case Card.CRTC.EGA.VBSTART: // 0x15
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.VBSTART_BIT8; // 0x08
bOverflowBit8 = Card.CRTC.EGA.OVERFLOW.VBSTART_BIT8; // 0x08
if (this.nCard == Video.CARD.VGA) bMaxScanBit9 = Card.CRTC.EGA.MAXSCAN.VBSTART_BIT9;
break;
case Card.CRTC.EGA.LINECOMP: // 0x18
bOvrflowBit8 = Card.CRTC.EGA.OVERFLOW.LINECOMP_BIT8; // 0x10
bOverflowBit8 = Card.CRTC.EGA.OVERFLOW.LINECOMP_BIT8; // 0x10
if (this.nCard == Video.CARD.VGA) bMaxScanBit9 = Card.CRTC.EGA.MAXSCAN.LINECOMP_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);
if (bOverflowBit8) {
reg |= ((this.regCRTData[Card.CRTC.EGA.OVERFLOW.INDX] & bOverflowBit8)? 0x100 : 0);
reg |= ((this.regCRTData[Card.CRTC.EGA.OVERFLOW.INDX] & bOverflowBit9)? 0x200 : 0);
reg |= ((this.regCRTData[Card.CRTC.EGA.MAXSCAN.INDX] & bMaxScanBit9)? 0x200 : 0);
}
}
@ -1152,6 +1154,18 @@ Card.CRTC = {
}
};
/*
* TODO: These mask tables need to be card-specific. For example, the STARTHIGH and CURHIGH registers used to be
* limited to 0x3F, because the MC6845 controller used with the original MDA and CGA cards was limited to 16Kb of RAM,
* whereas later cards like the EGA and VGA had anywhere from 64Kb to 256Kb, so all the bits of those registers were
* significant. Currently, I'm doing very little masking, which means most CRTC registers are treated as full 8-bit
* registers (and fully readable as well), which might cause some compatibility problems for any MDA/CGA apps that
* were sloppy about how they programmed registers.
*
* I do make an exception, however, in the case of STARTHIGH and CURHIGH, due to the way the MC6845 controller wraps
* addresses around to the beginning of the buffer, because that seems like a high-risk case. See the card-specific
* variable addrMaskHigh.
*/
Card.CRTCMASKS = {
[Card.CRTC.HTOTAL]: 0xFF, // R0
[Card.CRTC.HDISP]: 0xFF, // R1
@ -4068,7 +4082,7 @@ class Video extends Component {
* 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.CURLOW];
iCellCursor |= (this.cardActive.regCRTData[Card.CRTC.CURHIGH] & Card.CRTCMASKS[Card.CRTC.CURHIGH]) << 8;
iCellCursor |= (this.cardActive.regCRTData[Card.CRTC.CURHIGH] & this.cardActive.addrMaskHigh) << 8;
if (this.iCellCursor != iCellCursor) {
if (MAXDEBUG && this.messageEnabled()) {
this.printMessage("checkCursor(): cursor moved from " + this.iCellCursor + " to " + iCellCursor);
@ -5043,8 +5057,8 @@ class Video extends Component {
}
/*
* HACK: The CRTC's STARTHIGH and STARTLOW registers are supposed to be "latched" into
* offStartAddr ONLY at the start of every VRETRACE interval; this is an attempt to honor that behavior,
* HACK: The CRTC's STARTHIGH and STARTLOW 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.
@ -5059,7 +5073,7 @@ class Video extends Component {
* PARANOIA: Don't call invalidateCache() unless the address we're about to "latch" actually changed.
*/
var offStartAddr = card.regCRTData[Card.CRTC.STARTLOW];
offStartAddr |= (card.regCRTData[Card.CRTC.STARTHIGH] & Card.CRTCMASKS[Card.CRTC.STARTHIGH]) << 8;
offStartAddr |= (card.regCRTData[Card.CRTC.STARTHIGH] & card.addrMaskHigh) << 8;
if (card.offStartAddr !== offStartAddr) {
card.offStartAddr = offStartAddr;
this.invalidateCache();
@ -5848,7 +5862,7 @@ class Video extends Component {
* PARANOIA: Don't call invalidateCache() unless the start address we just "latched" actually changed.
*/
var offStartAddr = card.regCRTData[Card.CRTC.STARTLOW];
offStartAddr |= (card.regCRTData[Card.CRTC.STARTHIGH] & Card.CRTCMASKS[Card.CRTC.STARTHIGH]) << 8;
offStartAddr |= (card.regCRTData[Card.CRTC.STARTHIGH] & card.addrMaskHigh) << 8;
if (card.offStartAddr != offStartAddr) {
card.offStartAddr = offStartAddr;
this.invalidateCache();