What's new
haven't noticed any differences with gameplay other than reduced slowdown, which doesn't seem like a bad thing at all. Are there any documented problems with these?
Yea... reduced slowdown.
Doesn't seem like a bad thing? Ok, but understand that's your personal feeling.

FACT, its NOT 1:1 with the original as released by Capcom.
We could "document problems" with game play, but why bother with that effort only to arrive at the same conclusion (ie NOT 1:1)?

I'm not trying to badmouth the multi, I've been waiting with great anticipation like all of you.
I find it hysterical folks are going to the trouble of modifying C-boards for key operation, using original encrypted ROMs, only to run a 12mhz game/release on a 10mhz A-board.
Like patched ROMs are an inferior experience just by nature of being unoriginal code, but incorrect speed isn't a thing.
 
I think it's important to make a clear distinction between incorrect speed and reduced slowdown. When I hear "incorrect speed" I think that the gameplay loop is running too fast. That is a problem worth worrying about. But I don't think that's happening in any of these games. And that's what I'd like to know, if anyone has experienced that.
 
Otherwise, if the only difference is reduced slowdowns, then the simple thing is to source a 12MHz Dash motherboard and put the issue to bed. Capcom themselves re-released Daimakaimura, Strider, and Tenchi wo Kurau with the updated Dash motherboard late in the CPS1 lifecycle. These would have reduced slowdown compared to the originals, but not different baseline game running speed.
 
I think it's important to make a clear distinction between incorrect speed and reduced slowdown. When I hear "incorrect speed" I think that the gameplay loop is running too fast. That is a problem worth worrying about. But I don't think that's happening in any of these games. And that's what I'd like to know, if anyone has experienced that.
The speed issue has been discussed to death on many threads, like this one: https://www.arcade-projects.com/thr...rystal-oscillator-to-upgrade-an-a-board.5721/

@YesAffinity even made a video about it:

View: https://www.youtube.com/watch?v=b7ZK8SwFitY


There are also two topics pinned to this sub-forum which outline and compile a lot of information about CPS-1 "A-Board" differences and things related to "C-Boards".
 
Last edited:
Top 5

1 - cps1.5
2 - cps1.5
3 - cps1.5
4 - cps1.5
5 - cps1

:saint: :thumbsup:

giphy.webp
 
What about this “C” board?
126B3FB5-3E71-4614-BEC9-EA724BBCDC3D.jpeg

It has the B-21 and looks to never had the battery installed from the factory.
I tested and have continuity between B-21 pins 45&46 and 5V, can I just lift those and tie them to ground(no visible trace to cut)?
 
What about this “C” board?
126B3FB5-3E71-4614-BEC9-EA724BBCDC3D.jpeg

It has the B-21 and looks to never had the battery installed from the factory.
I tested and have continuity between B-21 pins 45&46 and 5V, can I just lift those and tie them to ground(no visible trace to cut)?

That board, even having the placeholder to install the battery, doesn’t have the capability to be key-programmed.
It lacks some components and traces that model 90631C-5 has, such as some diodes and resistor to avoid battery-powering the B-21 while the PCB is running on a cab, and some traces required to send the proper signals to B-21 to be programmed. So, that board will only work with patched romsets prepared to be run with B-21 in default mode (without decryption)

Saying that, it is possible to tune it up to make it behaves like 90631C-5 board. For the particular case of upcoming Darksoft multi-CPS1, battery-related stuff are not needed, but signal programming stuff are.

That modifications were only theorized initially, but we recently tried it with real PCB with success, so it could work and that could be a valid option to run the entire catalog.
Anyway, it is not an easy stuff to perform as it involves smd soldering and tracing here and there.


I think more details will be posted when it will be released. ;)
 
That board, even having the placeholder to install the battery, doesn’t have the capability to be key-programmed.
It lacks some components and traces that model 90631C-5 has, such as some diodes and resistor to avoid battery-powering the B-21 while the PCB is running on a cab, and some traces required to send the proper signals to B-21 to be programmed. So, that board will only work with patched romsets prepared to be run with B-21 in default mode (without decryption)

Saying that, it is possible to tune it up to make it behaves like 90631C-5 board. For the particular case of upcoming Darksoft multi-CPS1, battery-related stuff are not needed, but signal programming stuff are.

That modifications were only theorized initially, but we recently tried it with real PCB with success, so it could work and that could be a valid option to run the entire catalog.
Anyway, it is not an easy stuff to perform as it involves smd soldering and tracing here and there.


I think more details will be posted when it will be released. ;)
I followed the instructions in this thread so hoping I’m good to go.
https://www.arcade-projects.com/thr...a-90631c-5-battery-backed-b-21-c-board.13116/
I have no problem buying one of the other types but would rather leave those for other folks if this is a valid board after the modifications.
I’m extremely happy to see that the multi is in the testing phase and can’t wait for the release.
 
There's too much fuss these days over correct speeds, pixel perfection, what's missing, what's not right and not enough fuss over actual gameplay IMO. I grew up playing on RF and composite and if that's all I had today, I'd actually still enjoy my time playing whatever I could get my hands on.
Agree 100% here.

Also, running a 10MHz game on a 12MHz board and vice versa is probably how the arcade operators did it back in the ’80s and ‘90s anyway so this way is more “accurate”


:thumbsup:
 
Last edited:
I won't be buying a 12mhz A Board anytime soon. I have two short 10mhz boards and will stick to using them.

My top 5 will be:

1 - Cadillacs & Dinosaurs
2 - Knights of the Round
3 - Strider
4 - Ghouls'n Ghosts
5 - Any flavour of SF2 (including ridiculous hacks!)

So excited for this multi! If it's anywhere near as good as the CPS2 one, we'll all be very happy. Top work again to all those involved.
 
I will ask my question again for the OCD crazy guys, what about the idea of a socket for the crystal oscillator to switch between 10mhz / 12mhz, (a lot of old long boards are dead but likely have perfectly fine 10mhz oscillators), wouldnt this be easier than switching out A-boards every time? Are the oscillators/pins too delicate for something like this?
 
Right, I get that we're tying 45&46 to ground via pin 47. What i'm trying to say is rather than mess with those very close pins, why not take the jumper wire connected to 45&46 and just swing it over to ground somewhere else. That way you're not risking bridging the pins?
After doing this procedure, should I replace the battery again?
 
I will ask my question again for the OCD crazy guys, what about the idea of a socket for the crystal oscillator to switch between 10mhz / 12mhz, (a lot of old long boards are dead but likely have perfectly fine 10mhz oscillators), wouldnt this be easier than switching out A-boards every time? Are the oscillators/pins too delicate for something like this?
You can definitely do it, without any support in the multi you could rig two crystals to a switch to manually choose 10 or 12 mhz
 
You can definitely do it, without any support in the multi you could rig two crystals to a switch to manually choose 10 or 12 mhz
If you want to get fancy, If someone makes an oled selector, have them add a dual osc. mod that switches to either based on game selected or manually :D maybe @BladeZX can do something like that. Also, no need to get osc from dead boards, they are available.
 
You can definitely do it, without any support in the multi you could rig two crystals to a switch to manually choose 10 or 12 mhz
Sign me up! :D
 
Back
Top