The 5155's with the cloned MMC3 are wired for EPROMs on the PRG, but the CHR side still needs some rewiring.
Sorry to necrobump, but do you happen to have any more information on this? I have a few of these boards and would love to put them to some use.
On 53361-2 (MC-ACC), I can get it to boot a game, but the CHR side is corrupt. I have no issues with 51555-2 (MMC3B). Both are Roger Clemens MVP donors.
I'm using one 27C020 each for CHR and PRG (Mega Man 5), with 256k files in each. Some of the graphics and text look fine, but some are corrupt. I've read that this PCB may be compatible with 27C101
, and the only difference (from what I can tell) is pin 30 on a 27c101 is NC whereas it's A17 on a 27c020.
The other thing I noticed is that anything using the ACCLAIM-MC-ACC maxes out at 384Kb combined (the PRG+CHR I'm using is 512Kb). Could this have anything to do with it?
The first obvious difference I noticed was:
53361-2: pin Q0 (Eprom 13) -> cart pins 34 (CIC toPak) & 30 (PPU D0)
51555-2: pin Q0 (Eprom 13) -> cart pin 30 (PPU D0) only
53361-2: CIC pin 2 -> cart pins 34 (CIC toPak) & 30 (PPU D0)
51555-2: CIC pin 2 -> cart pin 34 (CIC toPak)
I matched up the wiring (as best I could) on the 53361-2 to match the 51555-2, but no change. PRG seems to work, but tiles are still missing from the CHR.
Any help is appreciated!
edit: I tried using Bonk's Adventure (another MMC3 TLROM) and same issue. It mostly works, but some tiles are missing. Is there any way to know if the issue is MC-ACC boards are trash or if it's the fact that I'm using 27C020 EPROMs? I may have some 27C101s to test with..?