CHA512Y

Just a quick question about the CHA512Y. I've got a boot that was faulty - I've replaced the 273 chip and decided to convert this boot into Diggerman. The board is supposed to use 4Mb or 8Mb chips and I am trying work out how best I can get the C ROMS on there. I've got plenty of 1Mb chips and 4Mb chips. Since the /BYTE pin doesnt exist on the 4Mb 27C322 etc then I guess its expecting the data in a different order or something? Any help welcome!

If you use 322s you need to make sure you set the jumpers correctly.

J2
J3
J7
J8
J9
J10

I just don't get why 1Mb chips didn't work, unless maybe I need to do some chunk / byte swap or something. I will try 4Mb ROMS later and just do them as is (linear) and see if that works. Thanks for the jumpers there!

I believe these boards only support 4MB/8MB mask roms. Everything you should need to know can be found here:

https://wiki.neogeodev.org/index.php?title=CHA512Y

Thanks! Will have a go with 4Mb chips! Total overkill using this board I know! It's mixed with a PROG16 so limited what I can use it for anyway.

You could use 1MB chips if it was only two. You would need to lift and jumper /Byte to +5V too.

Thanks! I just tried that with no joy =/ There's just a 512Kb C1 and 512Kb C2 - I basically doubled each up in the 1Mb chips - ie. C1 = 2 x C1, and C2 = 2 x C2 - just to be on the safe side, but it looks like its something related to distribute of odd / even bytes, I wonder if I need to split original C ROMs into odd and even. eg. odd C1 and C2 in one chip, and even C1 and C2 in the other? I would never have believed it would be so hard to get Diggerman working lol. I've four other boot conversions to games I need and they were a breeze compared to this. I will see what happens with 4Mb ROMs but I cannot imagine it would be any different than it is at the moment - looking like one C ROM is not being read correctly - ie. 50% correct. I will try and read that wiki page more tomorrow when I am not so tired, I might work out wtf I need to do then lol.

Too much work for a shitty game, bro.

8MB mask roms only use one enable, if your jumpers are wrong you would be putting A21 to the /CE of the eprom...that would give ya some funky sheet.

The C roms should all ready be split correctly for the 32bit data bus, C1 even, C2 odd


Jumpers for 4MB chips, same as 1MB except for /Byte

Short-JG1+JG2+JG3+JG4+J2+J3+J5+J6

Open-J1+J4+J7+J8+J9+J10+J11+J12

...and the game does indeed suck

mikey said:

I believe these boards only support 4MB/8MB mask roms. Everything you should need to know can be found here:

https://wiki.neogeodev.org/index.php?title=CHA512Y

Click to expand...

Xian Xi said:

If you use 322s you need to make sure you set the jumpers correctly.

J2
J3
J7
J8
J9
J10

Click to expand...

bustedstr8 said:

8MB mask roms only use one enable, if your jumpers are wrong you would be putting A21 to the /CE of the eprom...that would give ya some funky sheet.

The C roms should all ready be split correctly for the 32bit data bus, C1 even, C2 odd


Jumpers for 4MB chips, same as 1MB except for /Byte

Short-JG1+JG2+JG3+JG4+J2+J3+J5+J6

Open-J1+J4+J7+J8+J9+J10+J11+J12

...and the game does indeed suck

Click to expand...

Thanks! I had one jumper missing J10 I think. After putting 4Mb chips on there at the same time it works fine, but I suspect 1Mb chips would have worked had that jumper been set correctly as you say! Yes, it is a bit of a pants game, I just had nothing else to covert it to as I've either got the other games as original, boot or multicart etc, and the PRG board was a PROG16 which I think is limited on P and V size without hacking etc. I think I just need 3 or 4 games now - Jockey GP, Irritating Maze (or whatever its called, figure I might have to make some ADC input board as they are rare), Pochi & Nyaa (which is like hens teeth to find online), and Galaxy Fight.