Commodore 64 Service Manual (1985 Mar)
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The Service Manual, Model C64 Computer (March 1985, PN-314001-02) is Commodore Business Machines' service manual for the Commodore 64. It covers three board assemblies: 326298-01 (5-pin video), 250407-04 (8-pin video) and 250425-01 (the C64B). The 46-page scan has the numbered pages 1-32, the fold-out schematics, and Commodore's document change and registration forms at the end. The typed pages carry a text layer; the board layouts, pin assignments and schematics are images.
Contents
[edit | edit source]| Title | Page |
|---|---|
| Specifications | 1 |
| Product parts list | 2 |
| Block diagram | 3 |
| Circuit theory: power supply, reset logic, clock circuits | 4-6 |
| Circuit theory: I/O, ROM and expansion port; RAM control logic | 7-8 |
| Circuit theory: 5-pin and 8-pin video and audio outputs | 9-10 |
| Circuit theory: cassette interface; keyboard, joystick and paddle interfaces; serial interface and user port | 11-13 |
| Troubleshooting guide | 14-16 |
| Board identification | 17 |
| PCB assembly 326298-01: layout, parts lists, pin assignments, schematic 326106 | 18-22 |
| PCB assembly 250407-04: layout, parts list, modulator schematic 251025, schematic 251138, pin assignments | 23-27 |
| PCB assembly 250425-01: layout, parts list, modulator schematic 251696, schematic 251469, pin assignments | 28-32 |
What this manual settles
[edit | edit source]- The circuit theory names three versions: the 5-pin video machine (schematic 326106), the 8-pin machine (251138) and the C64B with its revised clock circuit (251469). Unless a section says otherwise it describes 326106 (p. 4).
- Component values for the three assemblies. On the 326298 list C19 is 2200 µF 16 V and C88 and C90 are 470 µF 50 V; on the 250407-04 and 250425-01 lists C88 is 1000 µF 25 V (pp. 19-20, 24-25, 29-30).
- Which parts Commodore stocked: the lists mark them with "C"; industry-standard resistors, capacitors and connectors were to be bought locally (p. 2).
- F1 is listed as a 1.5 A, 250 V normal-blow fuse; the power-supply drawing on p. 4 marks it 1 A.
What this manual does not contain
[edit | edit source]- The B-3 (250466) and E (250469) boards and the Commodore 64C; those are in the 1992 edition, PN-314001-03.
- A parts list or schematic for the B-2 (250441). The board identification page lists it and gives its changes from the B.
- The external power supply.
Other editions
[edit | edit source]- Commodore 64 Service Manual (1985 Sep): the same part number, contents list and assemblies, in a scan with a full text layer but with pages out of order.
- Commodore 64 / 64C Service Manual: March 1992.
Pages that cite this document
[edit | edit source]
Download: C64 Service Manual 314001-02 (1985 Mar).pdf (5 MB)