Centipede to JAMMA?

thebman80

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How do they build these adapters? I see the 22V and the -22V on the pinout and was just wondering how they boost the power to the board with the adapter. Anyone have any schematics on how to build a Centipede to JAMMA adapter?
 
I usually build my own but in this case it was more economical to save time and effort by buying one from arcadeshop or whoever else makes one like this:

http://www.arcadeshop.com/pics/centipede-jamma-adapter.jpg


Also buy a centipede to millipede adapter as well. Then you can work on both.



If you do want to make your own adapter, you will need to make the step up / step down voltages with parts like the classic intersil 7660S parts and also add an audio amplifier or connect the audio out to an amplified PC speaker.

At the end of the day, you will be better off buying the adapters. If you repair one or two boards and sell them, you have recovered your cost.

One other tip - I did build my own centipede to Missile command adapter using the centipede to jamma adapter and adding a couple of switches - saved cash there since the audio amp and trackball interface was already there.

Have fun,

Bill
 
How do they build these adapters? I see the 22V and the -22V on the pinout and was just wondering how they boost the power to the board with the adapter. Anyone have any schematics on how to build a Centipede to JAMMA adapter?


You don't really need voltages that high... if you don't care about saving scores (ie, just testing) it'll run fine off +5, +12, -5... you need the +22 to save scores, and a simple charge pump voltage doubler chip can pump the 12V up to (low current) 22 for you.
 
So the 22V is not necessary for the board to function then. Dont know how I would have supplied it short of ading an Atari Power supply to my test station Because I would also need -22v with the 22v and that's the only way I can think to provide that voltage. Might be a good addition further down the line but if its just for score saving then who really cares.
 
Wahoo figured it out the board seems to be a little flaky. Sometimes I have to turn it on and off like 4 times to get the game to pop up. First time I got it to worked I pressed down really hard on the bank of roms on the left side of the board and the game popped up. I resoldered all the roms and processor chips seems to work a little better but still flaky.

Now a few Issues, seems the the mushrooms only appear on the left side of the screen when the game starts and the fleas I guess that's what there called. When they drop down from the top of the screen they always make a solid wall of mushrooms are they suppose to do that? I thought they where only suppose to put a few random ones down the screen.

Few pictures:

DSCF2943.jpg


DSCF2944.jpg


DSCF2942.jpg
 
Fixed

Ok Problem has been fixed. I first replaced the C2 SY6502A chip with one from my spare Crystal Castles PCB and the game got a little less glitchey and one time turning it on and off the mushrooms where right as the should be then proceeded to go back to the left. I then popped out the C3 C012294B-01 chip next to the C2 and replaced it with one of my Crystal castles PCB the game is now working 100%. I wanted to make sure it just was the C3 chip so I proceeded to replace the C2 back with the old one and the game had some issues wouldn't turn on got green and blue screens then after putting the new C2 back everything was fine. So the C2 and C3 chips where bad on this board.

DSCF2947.jpg
 
LOL Christ this is the board from hell it started resting over and over I guess that's an indication that something else is on the horizon.:D Oh well I got to play centipede all day turning it off and on a few times fixed it but for how long....
 
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