Here is the schema:
cheap squeak
This soundcard is used in the following bally pinballs:
| Game | Rom Type | Jumper set | confirmed by |
| Black Pyramid | u3 (2532), u4 (2532) | J6, J9, J12 | volley |
| Cybernaut | u3 (2764) | ????? | |
| Fireball classic | u3 (2532), u4 (2532) | J6, J9, J12 | volley |
| King of Steel | u3 (2532), u4 (2532) | J6, J9, J12 | volley |
| u3 (2732), u4 (2732) | J7, J10, J11 | volley | |
| Spy Hunter | u3 (2532), u4 (2532) | J6, J9, J12 | okaegi |
| X's & O'S | u3 (2764), U4 empty | J2,J4,J7,(J10 only relevant if U4 is filled),j11 | volley |
Selftest LED Sequence
After power on, the 6803 performs a reset and starts the execution. First it fetches the address from startup routine from the U3 chip. This startup routine does a self test. Here you see the description of the self test:
| LED | after this... | if missing... |
| first flicker | the 6803 is started | |
| second flash | the checksum u4 is validated | replace u4 |
| third flash | the checksum u3 is validated | replace u3 |
| forth flash | the interal ram of the 6803 cpu ($80 - $ff) is validated | replace 6803 |
Selftest confirmed with
Kings of Steel
Spy Hunter
(Spy hunter has the startup routine placed in u4 not in u3, Spy hunter will not start the selftest if u3 or u4 is missing or corruped !)
Jumpers location
Mail me if you have additional information