I long to play some Atari System One games...

[vib_ribbon]

...and I hoped that I can make some sort of a JAMMA adapter for it to play in my cab.

When I looked at the pinouts...er...I'm all confused.

http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=pinout&page=Atari_System1.txt

I've only ever made a couple of simple straight forward adapters... but is it possible to turn this into JAMMA and if so, where do pins like "sense" and "+10.3" and "-15vdc" go??

Please help. Thanks.

[Rocky]

I made a System 1 to Jamma adaptor for testing. It just does power and video.

Because the system 1 main board has so many connectors, I don't know that it would be practical for a cabinet. Also, the system 1 main board + cartridge together won't fit in a lot of cabinets.

However, if you want to do it, here's the conversion to Jamma for power.

+15v ==> +12v
-15v  ==v  -5v
(both of these are for audio only so the different voltages only affect the power to the sound and are not a problem)

+10.3v unregulated ==> +12v
(this is needed to get the CPU to run)

+5vdc and ground are hooked to +5vdc and ground  .

You can connect the +sense to +5v  and the -sense to ground (or leave them disconnected).  The sense lines were for the atari power board to get feedback and adjust the power to the gameboard.

Good luck,
Rocky

[vib_ribbon]

Dear Rocky,

Many thanks for your help.

Does the JAMMA adapter plug into the white coloured socket on the motherboard? Could you take a photo of the adapter in the motherboard if it's not too much hassle?

Also, would you know where I can find the manual for the Atari System One?

Many thanks.

[Rocky]

My Jamma adaptor plugged into the 12 pin white connector on the main board and also into the video connector (P108, 8 pin connector)

You can get system 1 manual and scematics at this link:
http://arcarc.xmission.com/PDF%20Arcade%20Manuals%20and%20Schematics/

Download SP-277. It has a nice wiring diagram with pinouts.

I can't take a picture of my adaptor because I used it for parts on my Marble Madness cabinet.  I have 2 working system 1 cabs, so I didn't need the adaptor anymore.

[arcadefever]

rocky, thanks for that link 

[vib_ribbon]

hi rocky, thanks for all the help.

i see that P101 is the big white socket... but does P104, P105 and P108 offer a socket of some sort for a plug to go into? i hope i won't be hard soldering anything to the main motherboard...

am i even remotely on the right track?

[Rocky]

All of the connectors on the main board (except the 12 pin for power), are straight, in line pins.

Bob Roberts sells connectors that will work.  Don't solder directly to the main board.  All of the header pins are designed to have connectors put on them, not soldered.

[vib_ribbon]

that's great, that's all i need to know. thank you ever so much.