Hi Nicolas, >I built a hardware on my own now, which uses the concept I described in my >previous message. I based this on a dual 8k EXROM/ROML board for a 27128 >EPROM, with a latch made from a 74LS00 to switch off the EPROM by a write to >I/O2. I rewired the LS00 to do what I needed: two NAND gates form the RS-flipflop (/RES asserts /GAME, any access to I/O2 asserts /EXROM), >the other >two gates are used to form a combined chip select from /ROMH and /ROML. This >way I could put all your code into a single 8k bank and therefore install two >different diagnostic carts in one EPROM. I'll expand this to the third This is of course the most optimal way to do it! I still have many dead C64's though that fail to be diagnosed by the indicators. POWER is Ok, RESET is Ok, Clock OK, but ROML access is not (that is the cart never starts). I assume these to be a failed 6510 or PLA. Would that be correct? I also blew-up my first C64 for a long time about a month ago. The only thing I could put it down to was that I held the RESET line low (via the IEC port) for about 1.5-2mins (was swapping a bunch of cables with the C64 "on". The screen eventially garbled. Fortunately, it proved to be only the 6510 which was very very HOT. Is it common to kill the CPU with an extended RESET? - Nick PLEASE TAKE NOTE: The contents of this email (including any attachments) may be privileged and confidential. Any unauthorised use of the contents is expressly prohibited. If you have received this email in error, please advise us immediately (you can contact us by telephone on +61 8 9441 2311 by reverse charge) and then permanently delete this email together with any attachments. We appreciate your co-operation. Whilst Orbital endeavours to take reasonable care to ensure that this email and any attachments are free from viruses or other defects, Orbital does not represent or warrant that such is explicitly the case (C) 2000: Orbital Engine Company (Australia) PTY LTD and its affiliates Message was sent through the cbm-hackers mailing list
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