Dragon's Lair Fans - Arcade Lifestyle
General Chat => Technical Area => Topic started by: lesoleil70 on September 20, 2014, 09:42:34 PM
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Hi,
I've picked up a few pcb's over the last 12 months that have unique pin outs, with no information on KLOV etc. Some of the boards I've got, I've no idea what game they are.
I'm talking boards that I've got for silly cheap money, been given, traded, or were laying in the bottom of dead cabs etc. Quite a collection of crap that I'd like to just figure out.
What I was hoping to do here is have a fingerboard to jamma. so whatever these boards are, I can plug n play them.
Where do I start/what do I need to be able to identify:-
12v
-5v
+5v
gnd
sync
r
b
g
ground
controls
The one I'm interested in getting going first is a game that I DO know the identity of, it's a Blood Bros clone called West Story, the board is by Datsu. It's not Jamma, but it is 56 pin.
Here are some pics.
All help appreciated.
Ian you once told me how to do this...I wrote it down and lost the paper when I was in the middle of all the other cabs- I know that's just as crappy as "
my dog ate it", but it's true.
(http://oi57.tinypic.com/xf92rp.jpg)
(http://oi57.tinypic.com/2884aco.jpg)
(http://oi58.tinypic.com/r9qsd0.jpg)
(http://oi60.tinypic.com/2567ga1.jpg)
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Try dumping the roms and upload then to a romident site
If the rom is known you can ID the pcb
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Thanks, I appreciate that, good idea.
In the case above though I know the game, yet no pinout is documented.
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+5v and ground pins are usually easy to find; just take your DMM and trace back from some of the TTLs (i.e. find something like a 7404, with ground on pin 7 and VCC on pin 14, and go back from there).
Once you have done so and can hopefully power up the board, check for active pins, ideally with a scope. You should be able to find the sync signal this way, and identify the R/G/B pins (you'll have to try them out on a monitor to see what's what here, though).
Lastly, now that you have a picture, check for input pins by grounding each remaining pin selectively, and see what happens (or, if there's more pins than control options remaining, single them out first by searching for pins connected to pull up resistors).
Actually, there is a quite good and much more detailed guide on that process available here: https://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=info&page=Identify-unknown-boards.txt
Cheers,
Martin
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Keep in mind that older eproms 2704, 2708 need -5, 5, 12 volt. If you only apply one voltage you could kill them. Don't know exactly what the problem was but google it in case you have these old boards.
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Most of the ttl are from 91 and the eprom is a 27c02. The pinout looks very jamma like...
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Thanks everyone.