Multi JAMMA - selected with a rotary switch.

Tighe

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I know that this has been discussed before, but I had a slightly different approach here.

Here is one switch of many that have 8 decks each with one pole per deck. 12 Positions total on the switch.

http://www.digikey.com/product-detail/en/71B30-08A12N/71B30-08A12N-ND/1643896

I was thinking that really there are only 8 wires that need to be switched on a JAMMA harness, all the rest can be handled with diodes:


  1. +12VDC
  2. +5VDC
  3. -5VDC
  4. VIDEO BLUE
  5. VIDEO GREEN
  6. VIDEO GROUND
  7. VIDEO RED
  8. VIDEO SYNC

Ground can be connected all the time and the rest can be done with diodes:

  1. COIN COUNTER #1
  2. COIN COUNTER #2
  3. COIN SWITCH #1
  4. COIN SWITCH #2
  5. LOCK OUT COIL #1
  6. LOCK OUT COIL #2
  7. PLAYER 1 - BUTTON 1
  8. PLAYER 1 - BUTTON 2
  9. PLAYER 1 - BUTTON 3
  10. PLAYER 1 - DOWN
  11. PLAYER 1 - LEFT
  12. PLAYER 1 - RIGHT
  13. PLAYER 1 - START
  14. PLAYER 1 - UP
  15. PLAYER 2 - BUTTON 1
  16. PLAYER 2 - BUTTON 2
  17. PLAYER 2 - BUTTON 3
  18. PLAYER 2 - DOWN
  19. PLAYER 2 - LEFT
  20. PLAYER 2 - RIGHT
  21. PLAYER 2 - START
  22. PLAYER 2 - UP
  23. SERVICE SWITCH
  24. SPEAKER (-)
  25. SPEAKER (+)
  26. TEST SWITCH
  27. TILT (SLAM) SWITCH

I think that the rating should be high enough to handle the current used by a JAMMA board:

Contact Rating @ Voltage 0.25A @ 28VDC which if I am correct in my thinking would be 0.5A at 12VDC and approx 1A at 5V.

If it isn't there are other switches with higher ratings.

http://www.digikey.com/product-search/en/switches/rotary/1114210?k=rotary switch

http://www.nkkswitches.com/series.aspx?stid=6&id=5057

http://www.nkkswitches.com/pdf/hs_ps_ts.pdf


It sure would be cool to select games like a TV back in the day.
 
Interesting idea you've got there for sure Tighe.

I've been looking around for some sort of switching system as well. Everything I come up with involves a lot work... I've looked into printer switches, SCSI switches, rotoray switches, toggle switches... you names it! They all involve a lot of connectors, a lot of careful planning and a lot time to put together.

At the end of the day, I'm not if it's anymore cost effective then getting one of Clay's Multi-Jamma boards with the extra daughter boards or the 6-in-1 switch.

Sure would be a cool thing to put together though... :D
 
I know that this has been discussed before, but I had a slightly different approach here.

Here is one switch of many that have 8 decks each with one pole per deck. 12 Positions total on the switch.

http://www.digikey.com/product-detail/en/71B30-08A12N/71B30-08A12N-ND/1643896

I was thinking that really there are only 8 wires that need to be switched on a JAMMA harness, all the rest can be handled with diodes:

I think that the rating should be high enough to handle the current used by a JAMMA board:

Contact Rating @ Voltage 0.25A @ 28VDC which if I am correct in my thinking would be 0.5A at 12VDC and approx 1A at 5V.

If it isn't there are other switches with higher ratings.

http://www.digikey.com/product-search/en/switches/rotary/1114210?k=rotary switch

http://www.nkkswitches.com/series.aspx?stid=6&id=5057

http://www.nkkswitches.com/pdf/hs_ps_ts.pdf


It sure would be cool to select games like a TV back in the day.

I've thought of using this switch's smaller cousin in a test rig (for p1/p2 kind of thing). That's an expensive switch, but the real issue is you can't change the current rating on the contacts like that. The line of thinking you have there applies to transformers (where the power out == the power in) . The current rating on a switch or other similar devices. The current rating is just that.. the amount of current the device is designed to handle. The voltage has more to doe with the gap between contacts etc.
so... the upshot is, I wouldn't push 1A through a switch rated at .25 A.
cheers
/Tim
 
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