Hardware and Software Information

Assault had some ground breaking hardware and software for it's day. It featured a technology called "growth motion object hardware", which was responsible for the great scaling and rotational effects in the game. It also has full-fledged FM synthesis of sound effects and background music. Sadly, Assault wasn't as impressive as it could have been. There are quite a few features that weren't finished. Let me tell you about them....

The board is Namco System 2 with a JAMMA connector. There are two other connectors on the board - both unused. The schematics on the manual offer some hints as to what these connectors were designed for.

The JAMMA and sound connector with backplaneUnused 48-Pin Edge Card, next to the JAMMA connector. (see manual, p5-29) Note that this card edge isn't connected to the backplane. If you want to use it, you'll need to open up the metal cage to get directly to the PCB.


My custom sound connector This connector outputs Stereo sound! It just so happens the that sound connector uses the same pin widths as IBM PC connectors. I used an old MFM drive cable, but a floppy cable would have worked too. It's small enough to fit between the PCB and the backplane. Since the cable's connector was too small, I cut one end open with a Dremmel tool. I can get away with that since all the pins I care about are on that one side. It is possible to connect this wrong- be carefull!

Once you've wired up the headphone connections (see chart below), you can test the left/right orientation with the system's test mode. Play the FM sound #20- it will play a sound on left and then the right channel. Note that the volume control knob behind the coin door only affects the mono speaker. The headphone connections aren't affected.

Pin Label Description
A1 SPR+ Mono speaker +
B1 SPR- Mono speaker -
A2 PHR Headphone right
B2 PHL Headphone left
A3 3DL 3D sound left
B3 AGND Analog ground (for headphones)
A4 3DR 3D sound right
B4 3DCOM 3D sound common (not a ground!)
A5 -key-  
B5 -key-  
A6 GOUT(0) CPU connection. Possibly shutter glasses??
B6 GOUT(1)  
A7 GOUT(2)  
B7 GOUT(3)  
A8 GOUT(4)  
B8 n/a  
A9 VCC +5v
B9 GND Ground
A10 VCC +5v
B10 GND Ground
A11 n/a  
B11 <<RINGOUT CPU connection. Possibly shutter glasses
A12 >>RINGINK or network connection??
A13 <<RINGSW  
B13 <<SCOUT  
A14 >>SCINK  
B14 >>SCINA  
A15 ?? Connection to an IO chip??
B15 ??  
A16 ??  
B16 ??  
A17 VCC +5v
B17 GND Ground
A18 VCC +5v
B18 GND Ground
A19 AN(0) Unknown connection. Possibly the
B19 AN(1) network connection???
A20 AN(2)  
B20 AN(3)  
A21 AN(4)  
B21 AN(5)  
A22 AN(6)  
B22 AN(7)  
A23 <<ADVCC ??
B23 <<ADGND ??
A24 <<ADVCC ??
B24 <<ADGND ??


Unused connector in on the bottom PCBUnused 62 pin DIN connector on the bottom center of the PCB. (see manual p5-45). This connector goes straight to the "OBJ ROM" set of ROM chips. There are some near by jumpers, one of which directly powers off the built-in ROMs. My guess is that this connector is an expansion port for new levels. Plug in a card with some ROMs, move a few jumpers, and wa-la! You have a whole new game! I'm not skilled enough to create a new add-on card, but it does appear that it's functional.

Features shown in the game's "Test Mode", but not fully implemented:

Signs of a product rushed to market:

Manual misprints

Hand written fixes to the schematicsHand written fixes to the schematics




Other Interesting Notes.

Other Technical specs

(attach sound and music hardware information here)

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