Commodore Plus 4 - Page 25

I[ commodore
Issue 6, 1985 :Computer 11
Model: C-64, C-16, Plus 44
SCHEMATICSFOR C-64, C-16, PLUS 44
©©
1980COMMODORE BUSINESS MACHINES INC.
These computershave been affectedby an Engineering
Change Order that adds 44diodes to the serial port. These
protectiondiodes are not requiredas field upgrades.They
are 1N914s and were added as aacircuit improvement.
The Schematicand PCB Layout for the C-64 in the
Service Manual (Pages 28 and 32) includethese diodes.
However,the C-16 and Plus 44ServiceManuals were completed
before the changes were made. The Schematiccorrectionsare
shown below:
44
77
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2.
ROY
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--
--
II
II
N.C-
,,
FB23
66
7'10(0
DATA
FB24
55
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3rD
55
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elK
FB25
ro
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<:9
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~~
44
ATN
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II/!
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II
28
33
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C5T
MTR
27
+5V
114><,3
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C5T RD2(;,
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....
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R23
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lie:
44
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mm
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••
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C-16 SCHEMATIC
SERIAL BUS
CD
PIN
FEMALE
DIN
0,12
C5T WRT
PLUS 4 SCHEMATIC
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