xodaraP
Legendary
My 2 working A boards are both 10mhz - but I'm very tempted to modify the short board with an upgraded crystal, or maybe even a small board with a switch - I can set 10/12mhz as required
CPS A-Board Differences
- Thread starter twistedsymphony
- Start date
I could have sworn that the two versions of Dai-Makai mura were different. IIRC I modified MAME to spit out the maincpu region after loading.
I will revisit this, later this weekend.
For me I will just use two different A boards with a potential multi or make some kind of small PCB where I can switch the oscillator speed.
I will revisit this, later this weekend.
For me I will just use two different A boards with a potential multi or make some kind of small PCB where I can switch the oscillator speed.
Here are the two CPU dumps from daimakai and daimakair:
GAME( 1988, daimakai, ghouls, cps1_10MHz, "Capcom", "Daimakaimura (Japan)" // Wed.26.10.1988 in the ROMs
GAME( 1988, daimakair, ghouls, cps1_12MHz, "Capcom", "Daimakaimura (Japan Resale Ver.)" // Wed.26.10.1988 in the ROMs // 12MHz verified
They were created by modifying MAME to dump the main CPU memory region after the ROMs are loaded in the same fashion as with the CPS2 and F3 generator I wrote.
The files are clearly different.
Note:
The fill value is 0xff on daimakai and 0x00 on daimakair but even if we ignore this the files are different. For example at offset: 0x6
View attachment daimakai.zip
GAME( 1988, daimakai, ghouls, cps1_10MHz, "Capcom", "Daimakaimura (Japan)" // Wed.26.10.1988 in the ROMs
GAME( 1988, daimakair, ghouls, cps1_12MHz, "Capcom", "Daimakaimura (Japan Resale Ver.)" // Wed.26.10.1988 in the ROMs // 12MHz verified
They were created by modifying MAME to dump the main CPU memory region after the ROMs are loaded in the same fashion as with the CPS2 and F3 generator I wrote.
The files are clearly different.
Note:
The fill value is 0xff on daimakai and 0x00 on daimakair but even if we ignore this the files are different. For example at offset: 0x6
Code:
daimakai: 0x2e 0x19
daimakair: 0x96 0x1a
PascalP
Legendary
Here is a pic of my short boards, all 3 are exactly the same apart from the crystal.
2x are 12mHz and have a ‘Dash’ sticker and 1x is 10MHz
Only thing different I see is that the 10MHz board has a different 3.5MHz crystal and socketed Z80, but most likely due to repairs at some point.
All my other boards are long 10MHz boards so cannot compare more
The one on top is the 10MHz one;
2x are 12mHz and have a ‘Dash’ sticker and 1x is 10MHz
Only thing different I see is that the 10MHz board has a different 3.5MHz crystal and socketed Z80, but most likely due to repairs at some point.
All my other boards are long 10MHz boards so cannot compare more
The one on top is the 10MHz one;
PascalP
Legendary
based on this it seems the only differences between the short board and the dash board is the "CPS-Dash" sticker and the 12/10MHz crystal.
Muchi Muchi Spork
Student
Years ago I tried out the first version of Final Fight B+C boards on all 3 motherboard types that all worked and the only thing it would run on was the longboard. It's possible the same thing might happen with Forgotten Worlds, I guess.
A
Apocalypse
I know that, the ff instead of 00 doesn't affect code neither the other differences you found which are used to trace the version.
As most game boards and consoles CPS1 has a certain amount of CPU time between 2 vblanks. This period is fixed and doesn't change with the CPU speed. If all code can't be executed in this period a frame drop will occur resulting in a slowdown for the user. Code isn't modified for 12Mhz CPU, if there weren't any slowdowns when playing the game on a 10Mhz mainboard then there won't be any difference on a 12 Mhz motherboard. If there were slowdows then they may disappeared or be less frequent on a 12Mhz motherboard.
.
^ this.Your picture just shows a shorter B board (Mitchell, not a Capcom B board)
I have a Pang! 3 set and can confirm that the A Board is slightly different from a Capcom 12mhz one. For example, the ICs don't have "Capcom" on them and I *think* but I'm not 100% sure that the placement of some of the components are slightly different.
Can someone try using a Mitchell A board with other B-Boards and see if they work correctly? They should by all means, but who knows...
PascalP
Legendary
No one stated that the layout was the same. only that they were of similar size.
fluxcore
Enthusiast
The model and/or revision numbers of the boards would surely be different for different form factors...
You might want to add it to the list in your first post then.
I'll post pictures tomorrow.
The first post is about A-board difference, not b-board differences. I mean B-board differences is a whole other topic altogether if you want to start one yourself for that, by-all-means please do, but I don't want to go any further than the A-boards for the sake of this topic.
LHantz
Enthusiast
Just been checking a few CPS1 with a 12mhz (CPS Dash)
Carrier Airwing - works 100%
Mega Twins - Works 100%
Magic Sword - Works 100%
Captain Commando - Graphic errors and garbage on screen, sprites look OK, put back on 10mhz - works fine
I can check some more if needed
Carrier Airwing - works 100%
Mega Twins - Works 100%
Magic Sword - Works 100%
Captain Commando - Graphic errors and garbage on screen, sprites look OK, put back on 10mhz - works fine
I can check some more if needed
xodaraP
Legendary
Is that testing a 10mhz board with a 12mhz crystal? And Captain Commando played up until you put a 10mhz crystal back on it?
LHantz
Enthusiast
No it's 2 separate A boards
A
Apocalypse
What you say about CC is interesting. I had the same issue before and it turned out the PALs and graphic ROMs on the b-board didn't support overclocking. I also suspect some c boards to suffer the same issue. Not really an incompatibility problem regarding software but hardware limitation.