On 20/10/2013 21:56, Michał Pleban wrote: > > Then I'm afraid you either need to use two EPROMs, or two latches. Two > EPROMs, one RAM and one latch will unfortunately not fit in a cartridge. > Two latches, RAM and EPROM - maybe, I haven't tried but it's still hard. > Unfortunately if you do not switch to a larger EPROM, you may be stuck > with 8 kB images. I think it'll be larger eproms, I found some 040's for around £1 each. > >> How about AND'ing pin 10, which is /IO2 on the 64 and /CIA on the MAX, >> with A7? On the assumption that none of the MAX ROM's don't write to any >> of the CIA's mirrored registers during their normal operation we could >> use a write to $DC80 and $DF80 on the MAX and 64 respectively? > /IO2 is not /CIA on the MAX, it's the CIA's shift register output. Are you sure about that? According to the reverse engineered schematic on zimmers http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/c64/maxschematic.jpg the shift register is on pin 6 which is the dot clock on the 64. Pin 10 is /IO2 on the 64 and the CIA select signal from the MAX's PLA. Rob Message was sent through the cbm-hackers mailing listReceived on 2013-10-20 22:00:13
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