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Cleaned up the PDP-11 updateDisplay(s) code, and removed the update hack inside the WAIT instruction; display updates now occur in sync with the machine's 60Hz clock

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Jeff 2016-11-04 13:35:20 -07:00 • committed by Jeff Parsons
commit a7a44a8288
9 changed files with 485 additions and 460 deletions
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12
modules/pdp11/lib/cpuops.js
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@ -1754,13 +1754,13 @@ PDP11.opWAIT = function(opCode)
* NOTE: It's almost always a bad idea to add more checks to the inner stepCPU() loop, because every additional
* check can have a measurable (negative) impact on performance. Which is why it's important to use opFlags bits
* whenever possible, since we can test for multiple (up to 32) exceptional conditions with a single check.
*
* Finally, we used to update the machine's displays whenever transitioning to the WAIT state. However,
* it makes more sense to decouple display updates from specific instructions and rely on timers instead;
* the PDP-11 KW11 (60Hz Line Clock) timer is the perfect candidate. See device.js.
*
* if (!(this.opFlags & PDP11.OPFLAG.WAIT) && this.cmp) this.cmp.updateDisplays();
*/
if (!(this.opFlags & PDP11.OPFLAG.WAIT)) {
/*
* Since here we're actually transitioning to WAIT, let's update the Panel's LEDs (well, OK, among other things).
*/
if (this.cmp) this.cmp.updateStatus();
}
this.opFlags |= PDP11.OPFLAG.WAIT;
this.advancePC(-2);
this.nStepCycles -= 3;