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. The sound is the shift register shifting out bits to the CB2 pin, controlled by a timer. POKE 59466,15 E84A shift register value POKE 59467,16 E84B control register POKE 59464,freq E848 timer 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? > André -Olaf. -- ___ Olaf 'Rhialto' Seibert -- There's no point being grown-up if you \X/ rhialto/at/xs4all.nl -- can't be childish sometimes. -The 4th Doctor Message was sent through the cbm-hackers mailing listReceived on 2010-09-16 17:00:14
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