Issue 6, 1985 : Computer 1

Model: C-64, C-16, Plus 4

SCHEMATICS FOR C-64, C-16, PLUS 4

These computers have been affected by an Engineering Change Order that adds 4 diodes to the serial port. These protection diodes are not required as field upgrades. They are 1N914s and were added as a circuit improvement.

The Schematic and PCB Layout for the C-64 in the Service Manual (Pages 28 and 32) include these diodes. However, the C-16 and Plus 4 Service Manuals were completed before the changes were made. The schematic corrections are shown below.