Fascinating, thank you all for the explanations! On May 9, 2016 11:06 PM, "Julian Perry" <firstname.lastname@example.org> wrote: > Hello Ethan, > > Tuesday, May 10, 2016, 12:34:29 PM, you wrote: > > *> On Mon, May 9, 2016 at 1:51 PM, Kajtár Zsolt <*email@example.com > > > > > > > > > > > > > > *> wrote: >>> ...leave monitor, do poke 57088,123 and enter the monitor > again, you see this: >> Apart from the wrong cycle numbers it's just the > regular dummy read for fixing >> up the high part of address after > indexing. It's expected as it's not optional >> for a write. > This rings a > bell from my days of programming the Apple II... The I/O > there, unlike > CBM equipment, can be triggered by simply reading a > specific address > (writing specific values not required, unlike, say, > fiddling VIA or CIA > register contents). We had to be careful about > reads vs writes because > of that "double tap". > -ethan * <firstname.lastname@example.org> > That can happen with the CIA/VIA timers too, and was a common trick > (apparently) to clear both latches at the same time onthe Atari 2600's 6532 > RIOT. > > Julian > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2016-05-10 16:00:07
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