Burnaby, BC
Does the schematic show the -5 connection on any of the logic boards? It is unlikely to be used except for something like RS-232 communication, which I don't think was utilized in the game.
Certainly there is little risk for a game of this vintage to fire it up without the -5 to see if it boots up and plays fine.
If you do need the -5 you can add a regulator to the -12, there really shouldn't be much current drawn on either line - but you could put an ammeter in series with the -12 first to see what the draw is there prior to adding the -5 regulator.
There are +5 to -5 inverter schematics - somewhere...
John :-#)#
West Chicago, IL
