trs80gp updated to 1.5.1

Just finished a minor change to trs80gp, my TRS-80 emulator. The pause/break key wasn't activating the TRS-80 BREAK key on some computers. The problem was a little more involved than I realized. As Wikipedia hints, Pause/Break is a little unusual. On some systems, especially laptops, Windows will report the key is down and then immediately say it is up again — well before the key is actually released. I'm guessing this is a consequence of they key not actually reporting the up state at the hardware level. Windows is faking it to help programs operate.

This would be fine except that the emulated TRS-80 takes 2 or 3 frames to recognize the key. I presume that's to avoid keyboard bounce. Now what I do is artificially sustain the down time of any key which takes care of Pause/Break and should help with the emulator's propensity to miss keys. It wasn't so bad, but I did notice dropped letters when I was typing things into the emulator.

Thanks go out to John Otakie for pointing out the problem. If anyone notices bad side effects of this change, please let me know.

I even documented the keyboard mapping while I was at it.


George Phillips, November 2, 2009, gp2000 -at- shaw.ca