The SFEX 4mb motherboard is COH-1002C, I also have a COH-1002T on a raystorm. I don't see them listed in the mame driver.
There isn't a board layout in the source for coh1002c, but it's used in the emulation.
GAME( 1995, ts2, coh1000c, coh1000c, zn6b, zn_state, empty_init, ROT0, "Capcom / Takara", "Battle Arena Toshinden 2 (USA 951124)", MACHINE_IMPERFECT_SOUND )
GAME( 1996, sfex, coh1000c, coh1002c, zn6b, zn_state, empty_init, ROT0, "Capcom / Arika", "Street Fighter EX (Euro 961219)", MACHINE_IMPERFECT_SOUND )
I thought the difference between coh1000c & coh1002c was just the vram, the board notes for the coh1000c has 4mb on it.
The motherboard codes COH-1000C and COH1000T are the 2MB gpu ram versions of the same pcb's,
1 mb GPU (same as retail PSX)
Ram swap looks fairly simple just a case of working out the jumpers. As you say, the donor game might as well be a 4mb GPU game to save time.
2 mb GPU. We know roughly what the jumpers mean, because the game reads them to configure the ram controller.
------00 mem=4M
------01 mem=4M
------10 mem=8M
------11 mem=16M
-----0-- smem=hM
-----1-- smem=2M
----0--- vmem=1M
----1--- vmem=2M
000----- rev=-2
001----- rev=-1
010----- rev=0
011----- rev=1
100----- rev=2
101----- rev=3
110----- rev=4
111----- rev=5
I don't know where they are but I think it's classic pad + trace cutting & joining. There is only one possible setting for 8mb.
I don't know what chips you need to get 16mb, but if you can upgrade gnet to 16mb then I'd like to get mine upgraded. System 573 would be interesting as well. Should be possible to add a hard drive to that too.
I've not looked at what happens if you tell it you have 2mb of sound ram, instead of 0.5mb. The way sound memory is addressed it would likely make it incompatible with all existing software, so it's never been high on my list.
have you read this:
https://forums.arcade-museum.com/showthread.php?t=315445
The image shows 2 different ram layouts for the main board, it's a good enough pic of the main board to copy the ram layout.
Yeah I saw that. We have a board layout in the source already.
He also has the source code. And an undumped version by the looks... but no cat chips
You can see he has some cat chips, he's not got the roms that work on the target box.
Getting the source code from him is going to be somewhere between impossible and very impossible.
Interesting.. I always assumed they were the same as well. I'll have to go through my ZN stuff to see what's different. I'm hoping that at least the Capcom ZN2 main-board is standardized.
I think that by the time the ZN2 shipped, the cost of the RAM was less of an issue. The CPU was faster, so it didn't just receive lazy PS1 ports & you would want to justify going to the more expensive board. Capcom seemed to have gone with COH-3002C just in case they wanted to do a cut down version, while Taito was COH-3000T for GNET which came with 2mb of GPU RAM.
It needs someone with the hardware to assist to entertain that route that's for sure.
