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Fixed XXDP disk boot (haven't tried any tests yet, but it's still good progress)

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Jeff 2016-11-07 17:20:53 -08:00 • committed by Jeff Parsons
commit eb3b38a5ad
11 changed files with 163 additions and 125 deletions
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16
modules/pdp11/lib/cpustate.js
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@ -2042,20 +2042,26 @@ CPUStatePDP11.prototype.updateDstWord = function(opCode, src, fnOp)
* @this {CPUStatePDP11}
* @param {number} opCode
* @param {number} data
* @param {number} [writeFlags]
* @param {number} writeFlags (WRITE.BYTE aka 0xff, or WRITE.SBYTE aka 0xffff)
* @return {number}
*/
CPUStatePDP11.prototype.writeDstByte = function(opCode, data, writeFlags)
{
this.assert(writeFlags);
var reg = this.dstReg = opCode & PDP11.OPREG.MASK;
var mode = this.dstMode = (opCode & PDP11.OPMODE.MASK) >> PDP11.OPMODE.SHIFT;
if (!mode) {
if (!data) {
this.regsGen[reg] &= ~0xff; // TODO: Profile to determine if this is a win
} else if (writeFlags & PDP11.WRITE.SIGNEXT) {
this.regsGen[reg] = ((data << 24) >> 24) & 0xffff;
/*
* Potentially worthless optimization (but it looks good on "paper").
*/
this.regsGen[reg] &= ~writeFlags;
} else {
this.regsGen[reg] = (this.regsGen[reg] & ~0xff) | (data & 0xff);
/*
* Potentially worthwhile optimization: skipping the sign-extending data shifts
* if writeFlags is WRITE.BYTE (but that requires an extra test and separate code paths).
*/
this.regsGen[reg] = (this.regsGen[reg] & ~writeFlags) | (((data << 24) >> 24) & writeFlags);
}
} else {
this.writeByteToPhysical(this.getAddr(mode, reg, PDP11.ACCESS.WRITE_BYTE), data);