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Added PDP-10 JSP and JFCL operations (which seem to be the simplest means of getting and setting the processor flags)

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Jeff 2017-03-07 13:44:43 -08:00 • committed by Jeff Parsons
commit 7e207db2a1
8 changed files with 456 additions and 350 deletions
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54
modules/pdp10/lib/cpustate.js
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@ -336,14 +336,15 @@ class CPUStatePDP10 extends CPUPDP10 {
/**
* getPS()
*
* Gets the processor state flags in the format required by various program control operations.
* Gets the processor state flags in the format required by various program control operations (eg, JSP),
* pre-masked and pre-shifted for convenient loading into the left half of an accumulator.
*
* @this {CPUStatePDP10}
* @return {number}
*/
getPS()
{
return this.regPS & PDP10.HALF_MASK;
return (this.regPS & PDP10.HALF_MASK) * PDP10.HALF_SHIFT;
}
/**
@ -489,55 +490,6 @@ class CPUStatePDP10 extends CPUPDP10 {
this.regPC = addr % PDP10.ADDR_LIMIT;
}
/**
* abs(src)
*
* Used by the MOVM* (Move Magnitude) instructions.
*
* @this {CPUStatePDP10}
* @param {number} src (36-bit)
* @return {number} (absolute value of src)
*/
abs(src)
{
if (src > PDP10.MAX_POS36) {
if (src != PDP10.MIN_NEG36) {
src = PDP10.TWO_POW36 - src;
} else {
this.regPS |= (PDP10.PSFLAG.OVFL | PDP10.PSFLAG.CARRY1);
}
}
return src;
}
/**
* negate(src)
*
* Used by the MOVN* (Move Negative) instructions.
*
* @this {CPUStatePDP10}
* @param {number} src (36-bit)
* @return {number} (src negated, but as an unsigned 36-bit result)
*/
negate(src)
{
if (!src) {
this.regPS |= (PDP10.PSFLAG.CARRY0 | PDP10.PSFLAG.CARRY1);
}
else {
/*
* In the non-zero case, it's always safe to subtract src from TWO_POW36, but since we have to check for
* the MIN_NEG36 case anyway, and since subtraction in that case doesn't alter src, we skip the subtraction.
*/
if (src == PDP10.MIN_NEG36) {
this.regPS |= (PDP10.PSFLAG.OVFL | PDP10.PSFLAG.CARRY1);
} else {
src = PDP10.TWO_POW36 - src;
}
}
return src;
}
/**
* addIRQ(vector, priority, message)
*