> >> On 2017-04-18, at 13:56, firstname.lastname@example.org wrote: >> >> From your description of a sprite "almost?" touching the bottom of the >> screen... And the fact that it's always at the same position, so that >> it's >> really repeatable points to a logic error, not a timing error. >> >> Maybe it's a stuck sprite collision bit, that once set is not reset and >> keeps >> the interrupt low? > > For one, good example. > >> You could write a simple test program for that. > > Or check with the scope what happens with e. g. _IRQ line when it freezes. > Putting in a freezer car and checking if you get a repeatable freeze state > when it happens may also help. Provided you have an AR or similar. VIC-II can exhibit very strange failures. I have a stack of "partially failed" chips. One I recall works fine with everything, except programs that have sprites on the bottom border (like Paperboy). Any sprite moved down there displays as trash. -Pete Message was sent through the cbm-hackers mailing listReceived on 2017-04-18 13:00:43
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