wow, thanks... I didn't expect this. I'll still have to check if the rom depends on the other mappers. But this information might make a repro possible again.lidnariq wrote:This is really straightforward hardware to add. It's a 74'138 and a latch such as a (74'74 or 74'161) on top of a board already containing an MMC3.
Wire the 74'138 to detect writes to $41xx by connecting:
R/W to /G1a
A13 to /G1b
M2 to G2
/ROMSEL to A
A8 to B
A14 to C
74'138 /Y7 to latch CLK
CPU D2 to latch data in
latch data out to CHR A18.
Discuss technical or other issues relating to programming the Nintendo Entertainment System, Famicom, or compatible systems.
Seems it's not so simple. Trying to make repro of AV Mei Shao Nv Zhan Shi (Unl) If mmc3 completely ignore writing to $41xx then this game should work on mapper 04 (just with broken graphics).lidnariq wrote:This is really straightforward hardware to add. It's a 74'138 and a latch such as a (74'74 or 74'161) on top of a board already containing an MMC3.
Probably 116 mapper do something with mmc3 registers on writing to $41xx because game behaves wrong (on character selection screen and during fight I have freeze and garbled graphics).
For easier reproduction we can change code and move control register for CHR to $6000, because no WRAM in this game and we can use signals from mmc3 instead of 74'138 (like in mapper 189).
If only we can make the rest code work on mapper 4.
I've managed to remove protection from this rom, now it doesn't change mapper modes to vrc and mmc1. But circuit suggested earlier in this topic doesn't work properly (probably due to bus conflicts). So I 'm going to implement my idea to utilize wram /ce
- AV Mei Shao Nv Zhan Shi (Unl)[deprotected].ips
- Removes copy protection from original game. Now can be run on MMC3
- (105 Bytes) Downloaded 20 times
Any chance you have mapper hacks to something more conventional like MMC1 or MMC3 for Lethal Weapon (enforcers) or Cobra Mission pirate famicom games? They both use crazy stuff (mapper 90 or 118 I think?) I wanna play them on my real nintendo and not just on an emulator. Zapper and a CRT for lightgun games or GTFO right?