Dambusters Repair Logs

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Repairer: Paul Swan

BOARD NO: <operator owned>
GAME: Dambusters
MANUFACTURER: South West Research Ltd
DATE: 1981
HARNESS: MIDWAY-B(DC) (for testing)

SYMPTOM (30/08/96)



Fuel runs down far too quickly, ending the game almost instantly. High score table corrupt.

SOLUTION



This board is a complex factory conversion from a 'copy' Galaxians board set. A piggy back board held additional RAM and ROM along with a NiCd battery, leaking heaviliy. The battery was flat. Activating the test switch brought up the various game options but there seemed no means for resetting the corrupt battery backed RAM. I tried every conceivable button sequence & dip switch combination but to no avail. Replacing the NiCd battery with a new LiMH equivalent and leaving it on for a few hours "stabilized" the RAM contents but still left the game unplayable. In the end I wrote a small assembly routine that cleared every location to zero. It was written so that it could run from any location and autostart from any entry point. I also duplicated it to fill the whole space in the 2732 EPROM to improve the chances of it getting hit as I didn't know what the address space setup was. Replacing one of the program EPROM's with this EPROM, switching on, and then putting the original program EPROM back fixed the game and wiped all the stat's. If anyone wants an assembler for Z80, 8085, 6502, 6800 etc. then mail me.