It's possible to run the 6809 Taito games from a switching power supply. These Taito games (Zookeeper, Qix, Kram, Electric Yo-Yo and Space Dungeon) require a reset circuit (MRST) to boot the game at power on. This circuit is actually designed to reset the game in case the power drops below a certain voltage.

Switching power supplies only supply +5, -5 and +12 volts. The games want +5, -5, +12, -12 and MRST. You can simply connect -5 to the -12 wire on the harness and it'll work fine. You'll just have to turn up the volume a little more.

To create a fake reset circuit, build the following timer:

"A time delay should be connected to the reset line going to the board. You
will need a 1k 1/4 w resistor, a 1n4148 diode and a 10mf 25v capacitor.
Connect one end of the resistor and the banded end of the diode to +5.
connect the other end of the resistor and diode to the reset line. Connect
the positive lead of the capacitor to the reset line. Connect the negative
lead of the capacitor to ground." -- author unknown

Here's a diagram:




Here's the pinouts of the original power connectors:

Connector "J3"
==============
01/02|RED|+5V
03/05/07/11|BLK|Gnd.
04|BRN|-5V
06|YEL|+12V
08|ORG|-12V
09| |n/c
10|BLU|+12V
12|GRN|+12V
13| |n/c
14|WHT|MRST

Connector "J4"
==============
01/02|RED|+5V
03/05/07/11|BLK|Gnd.
04|BRN|-5V
06|YEL|+12V
08| |n/c
09| |n/c
10| |n/c
12| |n/c
13| |n/c
14|WHT|MRST

MRST is the reset circuit.

I also urge you to try to keep the original harness intact in case you ever want to go back to the original supply or you want to sell the game to someone who does. The connectors used for the power harness are common and the crimp tool to build an adapter that will plug into the original harness is fairly cheap too.

Questions and comments can be directed to me at:

tim@arcadecollecting.com