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So just remove the battery only?
Yes and you are ready to go!
 
We should include this in the instructions, I think.

Let me elaborate a bit. The reason why it must be unmodified, is in order to allow the B21 to be programmed for each game, so it will work 100% like the original.

If you hav a look at this, you will see that besides GND and VCC, 4 pins are needed:

https://github.com/ArcadeHacker/ArcadeHacker_CPS1/blob/master/Programmer Connections.png

Pin 42 in the B21 should go to pin 19 (Dark Green in picture above)
Pin 44 in the B21 should go to pin 20 (Light blue in picture above)
Pin 45 and 46 as explained, should be now connected to GND. Some hacks just cut the track with a Exacto knife, so you may need to run a wire to get those back connected to GND.
Pin 61 and Pin 62 are usually untouched and they would go to Yellow and Red respectively.
 
Good to Know on modified board that pin 42 and 44 musn't be GND, as they are on mine and other pic i watched on page post 7.
 
So I have one of those unscrupulously modified A boards that I bought before I knew anything about CPS1 hardware. It's a conversion to 1941. I'm handy with a soldering iron and was considering replacing all the crap components with decent audio-grade caps. Think it's worth the effort? I'd like to put it to good use and convert it to a multi. It has one of the "good" C boards as well.
 
Jury’s out on the chinesium audio mod. There’s a lot of components that are missing or subbed. You’d have to replace a lot. That being said the of the two boards I’ve had in my possession 1 came with issues, the other seems to be fine.
 
Jury’s out on the chinesium audio mod. There’s a lot of components that are missing or subbed. You’d have to replace a lot. That being said the of the two boards I’ve had in my possession 1 came with issues, the other seems to be fine.
Yeah, that makes sense. My board woks just fine. I just wonder if there's a "right" way to do it. I.E. replace the Chinese Audio mod with the components that would have existed on a legit Dash board.
 
This prompted me to check my 12 MHz A board that I've reserved for multi duty as I wasn't sure what I've got.

Looking at it now, it's definitely had the audio section added back in as the soldering on the SMT components is lower quality than elsewhere on the board, (I could've probably done a better job myself, but on the plus side they did use IC sockets!). However it looks like it's got real IC's; I can see what look like a genuine YM2151, YM3012, OKI chip and a full-sized amp with heatsink, unlike some of the photos I saw in the dedicated thread about these modded boards.

I've put a B+C on it from another board and it seems to behave so I think I'm good.
 
Question regarding CPS1 A Boards. I have a 12mhz A Board from a Pang I’m planning on using. Question is, the tantalum caps, are those wet or dry? Deciding if they should be replaced with the other caps. Im guessing no but figured I should ask. Thanks!
 
A B-05 and a B-21 on the same C board? And it’s factory?! What is this thing from?
 
A B-05 and a B-21 on the same C board? And it’s factory?! What is this thing from?
I'm pretty sure the B-05 was the original chip and it's just sitting there in the photo for comparison.

SF2: WW used that C-board and the B-05 but the kick header isn't populated which is weird.

the only other game I know of that used B-05 is 1941 but usually it's on a more compact C-Board PCB.
 
That board was for Street Fighter2 WW. I removed the kick harness header and related hardware because I needed the PAL socked for the "IOC1" PAL which B-21 requires. Instead of using the original "IOC1" PAL I used the "BGSA5" from the very same CPS2 A board I gutted the B-21 from.

The kick harness enable signal is generated by the "C632" PAL which was what was originally on that PAL socket.
 
Yes! Both 10 and 12Mhz boards are compatible, just make sure that the Audio section in the A Board is populated. If the board comes from a CPS1.5 Board it won't be populated as it uses Qsound.
I could purchased a knight of the round. I am wondering know, because the A board of Kotr should be a 10 Mhz, whether I should not look for a street fighter II dash for its Cps dash A board as a complement. What would append to the Cps 1.5 games on a 10 Mhz A board? Becoming slow ?
 
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