Den Fri, 26 Oct 2018 16:47:15 +0200 skrev silverdr@wfmh.org.pl: > > > On 2018-10-26, at 16:33, Francesco Messineo > > <francesco.messineo@gmail.com> wrote: > > > >>> Now to the interesting case. I've got a CIA that passes all the > >>> diagnostic tests, > >> > >> My impression is that in general the tests aren't that throughout > >> and can miss stuff. > > > > This is surely the case. It's a complex task to very well test a > > Complex Interface Adapter ;) > > True. Just here those are simply port bits. I'd need to check if > there is a way to test those both directions. Maybe it's tested only > one direction. And maybe there is no easy way to test it both > directions. But if there is, and it's not tested that way then this > is another point to add to my list of things to improve in the test > cart's software I use. For the CIA pins that select VIC 16k bank, you could use the VIC sprite collision hardware to by software detect which 16k bank VIC is reading data from. You might be able to with some kind of super exact timing set up VIC to use the sprite collision detection hardware to read certain parts of memory (I.E. set it so the collision data would indicate if VIC did read from 16k bank 0,1,2 or 3) and then time it so that the CPU flips the CIA VIC bank pins exactly the moment before VIC actually does the read. This might or might not be able to detect problems related to incorrect logic levels as the transition might be a bit slower or a bit faster. It will probably not make much difference though. An oscilloscope on these signals would probably tell if it's worth the effort trying to code something like this. Btw afaik reading back an output port will actually read the pin status, so if there is a short circuit you can afaik detect that even with the pins in output mode. -- (\_/) Copy the bunny to your mails to help (O.o) him achieve world domination. (> <) Come join the dark side. /_|_\ We have cookies.Received on 2018-10-26 18:00:36
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