Unique visits: 7276 Can you help getting more info about those carts?

Type multi Mapper 923 Original mapper 0+2 PCB marks 8-27-C-A ET-89 Tags: Uploaded: 2020-03-30 09:21:24

   fedcba9876543210     76543210
   1001000101100010
A~[1......AXBabcdMV] D~[.....klm]
          |||||||||          |||
          |||||||||          +++- PRG bank in UNROM mode
          ||||||||+-------------- NROM PRG size: 0=16K, 1=32K
          |||||||+--------------- mirroring: 0=V, 1=H
          |||++++---------------- PRG bank in NROM mode
          ||+-------------------- PRG-A18 
          |+--------------------- PRG mode (1=CHR-RAM is write-protected)
		  +---------------------- PRG-A19 & PRG mode (1=this register is write protected)
		   
AXV $8000  $c000
000 0Babcd 0B0000
001 0Babc0 0B0000
010 0Babcd 0Babcd
011 0Babc0 0Babc1
10* 1Baklm 1Ba111
11* 1Baklm 1Baklm


//DUMPING:
for (int bank = 0; bank < 64; ++bank) {
	buttonSimulateReset.PerformClick();
	int adr = 0x8000 | shi(bank, 0, 2) | shi(bank, 1, 3) | shi(bank, 2, 4) | shi(bank, 3, 5) | shi(bank, 4, 6) | shi(bank, 5, 8);
	cpu_write(adr, new byte[] { (byte)(bank & 7) });
	if (bank < 32) {
		cpuRead(0x8000, 0xbfff);
	}
	else {
		byte[] c000 = cpu_read(0xc000, 0x4000);
		for (int unrom_bank = 0; unrom_bank < 8; ++unrom_bank) {
			bool found = false;
			for (int unrom_addr = 0; unrom_addr < 0x4000; ++unrom_addr) {
				if ((c000[unrom_addr] & 7) == unrom_bank) {
					cpu_write(0xc000 | unrom_addr, new byte[] {c000[unrom_addr]});
					cpuRead(0x8000, 0xbfff);
					found = true;
					break;
				}
			}
			if (!found) {
				throw new Exception(String.Format("Bank {j} not found", unrom_bank));
			}
		}
		bank += 8;
	}
	
}
Quite weird cartridge mixing NROM128, NROM256 and UNROM mappers, allowing to run multiple games from each one. Dumping the second part (when A=PRG-A19=1) was tricky because after figuring exactly how the mapper works, cartridge needs simulated restart after each write (address latch locks when writing with A=1). Additionally, there are bus conflicts so after each write, $c000-$ffff needs to be read back first to see at which address value to be written exists.
Additionally,

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