----------------------------------------------------------------- | Q*BERT TO JAMMA | ----------------------------------------------------------------- COPYRIGHT 2001 REVISION NUMBER: 1.0 REVISION DATE: 09 March 2001 CREATED BY: Rick Schieve STANDARD DISCLAIMER: -------------------- REMEMBER, NO WARRANTEES, EXPRESS OR IMPLIED, ARE GIVEN. USE THIS INFORMATION AT YOUR OWN RISK. I AM NOT RESPONSIBLE FOR ANY DAMAGES THAT MAY OCCUR TO YOUR PERSON OR PROPERTY. ----------------------------------------------------------- GENERAL OVERVIEW: ----------------- My goal was to make Q*bert plug into a JAMMA harness with as few modifications as possible. Q*bert outputs seperate video syncs, requires a couple of non-standard voltages and has an offset joystick. INGREDIENTS: ------------ 1 - Working Gottlieb Q*Bert Board 1 - 74LS04 (14 pin Hex Inverter) 1 - 74LS08 (14 pin Quad 2 Input POS AND gate) 1 - 74LS32 (14 pin Quad 2 Input OR gate) 1 - JAMMA Fingerboard 1 - 56-pin edge connector 1 - spool of jumper wire INSTRUCTIONS: ------------- Plug the JAMMA fingerboard into the JAMMA connector in your game/test fixture. Then plug the 56-pin edge connector into the Q*bert circuit board. Solder jumper wires from the 56-pin edge connector to the JAMMA fingerboard re-routing the controls, power and video signals in accordance with the JAMMA standard. Details are provided below. The first issue is that Q*bert puts out separate active high H and V syncs and JAMMA wants an active low composite sync. I experimented with several circuits but the one that seemed to work the best for the monitor that I was using was to first invert each sync (with a 74LS04) and then AND the separate syncs (with a 74LS08). Again, this is what worked best for the monitor I was using. Sometimes it's easier to abandon trying to combine the syncs and just connect the separate syncs directly. The next issue is the +30 VDC required by the audio amp on the sound board. After looking over the schematics I determined that the only thing that uses the +30 is the final audio amp, U23, an LM379S. My solution to the fact that the LM379S needed +30 (not provided by JAMMA) was to simply not use the LM379S amp. For the Q*bert JAMMA adapter, don't connect anything to the +30 VDC or the sound board audio output (pin 7). Instead wire up an external amp with the output directly connected to the speaker. For the input of the external amp, solder a wire on to the bottom of the sound board at pin 9 of U23 (the on-board amp's input). Now, the external amp does all the work. The other non-JAMMA power supply voltage required by Q*bert is -12 VDC. I suspect that you could get away with powering the -12 with the JAMMA -5 but didn't try it myself. Enough of the older games required -12 to make me supply that voltage with a separate supply and connector. The last complication is caused by the fact that the joystick for Q*bert is rotated 45 degrees from the way a standard joystick is mounted. It is a standard 4-way stick, it's just turned 45 degrees. This is why the pinout info contains connections for things like "DOWN-RIGHT" on a single pin. I didn't want to remount a stick so I took advantage of a suggestion by Mark Jenison (I mentioned your name Mark, are you happy now? :-) ) and used 4 "OR" gates on a single 74LS32 to make an 8-way standard joystick do the job without rotating its mounting. The wiring went like this: Joystick Q*bert input up ----1 \ ---- 3--- up-left left ---2 / up -----4 \ ---- 6--- up-right right --5 / down --10 \ ---- 8--- down-left left -- 9 / down --12 \ ---- 11-- down-right right -13 / I also added 4.7K (again, a non-critical value) pull-up resistors between each joystick connection and +5. Normally the game board provides the pull-up resistor but here its needed at the joystick to pull the inputs high. The joystick contact closure brings the inputs low. With this scheme 2 adjacent inputs going low when the joystick is moved to 45, 135, 225, or 315 degrees gives one low output in the direction required by Q*bert. I suspect the joystick is more difficult to use than if you really rotated a 4-way joystick but the game is definitely playable. I know some of you will be disappointed but I didn't connect a cabinet knocker since it requires +30 VDC, but you gotta make some hard decisions at times ;-) Well, I hope you people found this interesting. Thanks to Mark Jenison who worked with me on the adapter and to Kevin Klopp (alias mowlawnman) for loaning me his working sound board to help me debug mine. OTHER HELPFUL Q*BERT/JAMMA INFORMATION: ---------------------------------------------- Q*BERT PINOUTS CPU MA-378 (A1) _______ +5V |A | 1| GND +5V |B | 2| GND +5V |C | 3| Coin Return GND |D | 4| Coin 1 |E | 5| Coin Lockout Coin Meter |F | 6| Knocker |H | 7| |J | 8| |K | 9| |L |10| A6 P1-2 (SB) |M |11| |N |12| A6P1-4 (SB) |P |13| Select Test SW |R |14| GND Coin SW #2 |S |15| Step Test SW Coin SW #1 |T |16| 1P Start |U |17| 2P Start |V |18| Up-Left |W |19| Down-Right |X |20| Down-Left Up-Right |Y |21| A6P1-8 (SB) |Z |22| A6P1-9 (SB) A6P1-11 (SB) |a |23| A6P1-12 (SB) Vertical Sync |b |24| RED |c |25| BLUE Ground (monitor) |d |26| GREEN Horizontal Sync |e |27| +11.5V +5V |f |28| GND +5V |h |29| GND +5V |j |30| GND ------- JAMMA PINOUTS COMPONENT SIDE SOLDER SIDE _______ Gnd |1 | A| Gnd Gnd |2 | B| Gnd +5vdc |3 | C| +5vdc +5vdc |4 | D| +5vdc -5vdc |5 | E| -5vdc +12vdc |6 | F| +12vdc key |7 | H| key Coin counter 1 |8 | J| Coin Counter 2 |9 | K| Speaker + |10| L| Gnd (speaker) |11| M| Video Red |12| N| Video Green Video Blue |13| P| Video Sync Gnd (Video) |14| R| Service Switch |15| S| Coin Sw. 1 |16| T| Coin Sw. 2 Start 1 |17| U| Start 2 1P Up |18| V| 2P Up 1P Down |19| W| 2P Down 1P Left |20| X| 2P Left 1P Right |21| Y| 2P Right Push 1 |22| Z| Push 1 Push 2 |23| a| Push 2 Push 3 |24| b| Push 3 Spare 1 |25| c| Spare 1 Spare 2 |26| d| Spare 2 Gnd |27| e| Gnd Gnd |28| f| Gnd ------- ----------------------------------------------------------------- | END | -----------------------------------------------------------------