JAMMA adapters and sync

modessitt

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I asked about this in the Monitor section, but got no input.

've been wondering how JAMMA adapters deal with games that have separate synce, instead of composite sync? My K7000 test monitor usually only wants the composite sync on the horizontal pin (but seems to work okay with it hooked to both horizontal and vertical), so I figure I can just connect the horizontal to the JAMMA sync output, but what about if I use it with a G07 or something? Will it still sync?

Thoughts?
 
I used the circuit described by Rick Shieve for my Qbert Jamma adapter to combine the h and V sync. It works great and I have used it a few times with great success:

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

"first invert each sync (with a 74LS04) and then AND the separate syncs (with a 74LS08)."

The output of the LS08 goes to the composite sync input of your monitor.

Bill
 
I used the circuit described by Rick Shieve for my Qbert Jamma adapter to combine the h and V sync. It works great and I have used it a few times with great success:

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

"first invert each sync (with a 74LS04) and then AND the separate syncs (with a 74LS08)."

The output of the LS08 goes to the composite sync input of your monitor.

Bill

Using just a single 74LS86 works just fine with Q*bert to get a composite sync out

1 -> H-sync from board
2 -> V-sync from board
3 -> to pin 4
4 -> to pin 3
5 -> 1k resistor to +5v ( for negative composite sync )
6 -> composite sync output
7 -> GND
14 -> +5v

- James
 
I've had several cabinets with G07's and JAMMA harnesses. All but one just loop the sync line to both pins and about 25% add the ground line from the RGB connector. The G07s seem to be able to sort the sync signals out.

ken
 
Using just a single 74LS86 works just fine with Q*bert to get a composite sync out

1 -> H-sync from board
2 -> V-sync from board
3 -> to pin 4
4 -> to pin 3
5 -> 1k resistor to +5v ( for negative composite sync )
6 -> composite sync output
7 -> GND
14 -> +5v

- James

The venerable 74LS86 - I'll give it a try next time. one chip beats two any day.

Bill
 
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