Help,I have been working on the verification of this cartridge during this period of time, but I still haven't succeeded. I hope you can help me to describe the logic of (CPU_R_nW, CPU_ROMSEL, CPU_A14, CPU_A13, CPU_A12) and (VRC4_900C). I use some logic chips to realize it.I think that's the problem.krzysiobal wrote: ↑Mon Apr 12, 2021 2:45 am I will make the cartridge in free time to verify. Honestly I would prefer the AX5202P (MMC3) as this chip is more common and all Street Fighter versions I have encountered so far used it, but that would require modifying the ROM.
City Figher 4 with ext audio (Mapper 266)
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Re: City Figher 4 with ext audio (Mapper 266)
- krzysiobal
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Re: City Figher 4 with ext audio (Mapper 266)
q5911 wrote: ↑Thu May 27, 2021 10:19 pm Help,I have been working on the verification of this cartridge during this period of time, but I still haven't succeeded. I hope you can help me to describe the logic of (CPU_R_nW, CPU_ROMSEL, CPU_A14, CPU_A13, CPU_A12) and (VRC4_900C). I use some logic chips to realize it.I think that's the problem.
* Sorry, I was wrong in the reverse engineer: VRC pin 3 should be CPU-A3 and VRC pin 4 should be CPU-A2, not vice versa
* Because VRC-CPU-A13=CPU-A14 and VRC-CPU-A14=CPU-A13 and VRC-PRG-A14 seems to be PRG-ROM-A14 and VRC-PRG-A13 seems to be PRG-ROM-A13, it means that current order of banks in dump does not match the physical way they are ordered in the EPROM. The best fix is to rewire VRC-PRG-A14 to PRG-ROM-A13 and VRC-PRG-A13 to PRG-ROM-A14
* After those two corrections, you should be able to run game with your current wiring and current PAL. However, if you're really sure your VRC does not have $9003, I was able to squeeze almost every logical input inside the PAL (the one that did not fit was CPU_ROMSEL and CPU_RnW - you have to OR-them externally (for example using diode and resistor) and fed into PAL. Use the attached schematic and attached PAL fusemap.
Code: Select all
CPU /ROMSEL -1k--+--- nROMSEL_or_RnW
CPU R/W -----|>--+
* PAL pin 1 = nROMSEL_or_RnW
* PAL pin 2 = CPU A11
* PAL pin 3 = not connected
* PAL pin 4 = CPU A14
* PAL pin 5 = CPU A13
* PAL pin 6 = CPU A12
Or to use the VRC $9003:
* PAL pin 1 = VRC $9003
* PAL pin 2 = CPU A11
* PAL pin 3 = not connected
* PAL pin 4 = GND
* PAL pin 5 = GND
* PAL pin 6 = VCC I've just make a test cartridge for it (what is wired to PAL pin 1/4/5/6 selected using jumpers) and it works in both ways
- Attachments
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- proj_eqn+jed+log.zip
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Re: City Figher 4 with ext audio (Mapper 266)
yes! It's really working. I even heard the rough PCM sound. It's really grungy.After those two corrections, you should be able to run game with your current wiring and current PAL.
Thank you for your contribution!
Re: City Figher 4 with ext audio (Mapper 266)
Great, did you fully replicate it? Is there a test video?