Colordreams Attempt #3

196 board

Circuit Diagram

How it works:

They seemed to have learned that the Rube Goldberg circuitry with the germanium diode was not required. This is a refined version with that missing. Like the others, the software must operate this lockout defeat during startup for it to work properly.

Circuit Operation:

The ICL 7660 chip generates -5V using 2 capacitors. There are two identical circuits here which are simply voltage translation, so that the 5V logic from the mapper chip can switch the -5V on and off to the lockout pins. I don't know why there is a diode on pin #35- it is effectively shunting the -5V supply to ground when the transistor turns on.

When D2 (or D3) is high, it turns -5V on to its respective cart pin.

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