Jim, Considering the purpose of this cart is to eliminate the need to desolder a kernal rom, would you be against using a clip to the 6510's PIO pin to en/disable your ultimax trigger depending on the port pin? This would only be one lead to run into the system. I can't think of a good way of doing this from outside the c64, but I'd love to hear others' input. :) -jbev On Thu, 18 Nov 2010, Jim Brain wrote: > Given the fact that many C64 machines have non socketed KERNAL ROMs, I > continually receive requests for a KERNAL ROM cart. > > Academically, I see how to do it by driving ULTIMAX mode during > $e000-$ffff reads, but that only works when RAM is banked out. Does > anyone have an ideas on how to accomplish that? > > I know I could implement a mirror for $0 and $1, but folks say those > addresses and the R/W signal don't show on the external bus. > Implementing a complete 6510 on the cart to mirror the internal 6510 > might work (discarding write operations), but that's truly a brute force > approach and hardly seems worth the effort. > > Jim > > -- > Jim Brain, Brain Innovations (X) > firstname.lastname@example.org > Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times! > Home: http://www.jbrain.com > > > Message was sent through the cbm-hackers mailing list > Message was sent through the cbm-hackers mailing listReceived on 2010-11-19 06:00:15
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