Commodore PLUS 4 Service Manual page 25

Issue 6, 1985 :Computer 11
Model: C-64, C-16, Plus 44
SCHEMATICSFOR C-64, C-16, PLUS 44
These computers have been affected by an Engineering
Change Order that adds 44diodes to the serial port. These
protectiondiodes are not required as field upgrades.They
are 1N914s and were added as aacircuit 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 44Service Manuals were completed
before the changes were made. The Schematiccorrectionsare
shown below:
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PLUS 4 SCHEMATIC
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