On 9/16/10, Rhialto <rhialto@falu.nl> wrote: > On Thu 16 Sep 2010 at 10:38:30 +0200, "André Fachat" wrote: >> I voted for the 6522 as next chip to analyze, to find out about the >> shift register bug. > > Speaking of shift register bugs: there is this one that I don't remember > being explained. If you enable sound on a PET, then try to load anything > from cassette, the PET hangs. The STOP key does not work, nor does > anything actually load. Yes. I remember that one (especially since a lot of my early work was fiddling with CB2 sound and I didn't own a disk drive). > See > http://www.commodore.ca/manuals/commodore_pet_2001_quick_reference.pdf > which also notes "NOTE: Location 59467 must be reset to zero for > cassette to function properly". But that shift register isn't used for > cassette loading, right? It's not, but ISTR some vague stories about putting the shift register into free-running mode (which is how one gets sound) triggers some hidden problem. I'd love to know what is _really_ going on in there (not that we could fix the problem). I'm suddenly curious if the 65C22 has the same issue (I have a few of each; I should try it). -ethan Message was sent through the cbm-hackers mailing listReceived on 2010-09-16 17:00:31
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