2001 Main Logic Assembly
Main Logic Assembly Parts Cross Reference — Commodore Business Machines, Inc., Palo Alto, California. Three sheets, scanned at 400 dpi, giving every component on the Commodore PET 2001 system board by reference designator, description and Commodore part number.
This is a parts list, not an assembly drawing. The page title is Commodore's own sheet heading abbreviated, but a reader expecting a board layout or an exploded view will not find one: there is no placement drawing for the main logic board anywhere in this document, and none is known to be hosted on this wiki. The display assembly does have one — Video Board Parts Layout.
This file is a duplicate upload. 2001_main_logic_assembly.pdf is byte-identical to File:Commodore PET 2001 Main Logic Assembly Parts List.pdf, the copy cited from Commodore PET 2001 Service Documentation and Commodore PET 2001 Capacitor Replacement Guide. The same three sheets are also on this wiki as high-resolution GIFs at System Board Parts List (1 of 3), System Board Parts List (2 of 3) and System Board Parts List (3 of 3).
What it establishes
[edit | edit source]| Position | Part | Commodore part no. |
|---|---|---|
| C7–C10 | 47 µF 16 V electrolytic — the only aluminium electrolytics on the board | 900100-33 |
| C5, C11, C12, C13 | 1.0 µF 25 V tantalum | 900402-13 |
| C15–C49 | 0.1 µF 10 V ceramic | 900010-39 |
| UF3 | 6502 MPU | 901435-01 |
| UB8, UG8 | 6520 PIA | 901436-01 |
| UA5 | 6522 VIA | 901437-01 |
| UC3, UC4, UI1–UI8, UJ1–UJ8 | 6550 RAM (assemblies 320008, 320081) | 901438-01 |
| UC3, UC4, UI1–UI8, UJ1–UJ8 | 2114 RAM (assemblies 320132, 320137) | 901453-01 |
| UA2 | 6540-010 character generator | 901439-08 |
| UA2 | 2316B-08 character generator | 901447-08 |
| UH1–UH7 | 6540-011/-012/-013/-014/-015/-016/-018 ROMs | 901439-01 to -07 |
| UH1–UH7 | 2316B-01 to -07 ROMs | 901447-01 to -07 |
| UA7, UA8, UA9 | MC3446 IEEE-488 bus transceiver | 901524-01 |
| Q1, Q4 | TIP29 — cassette motor drivers, not regulators | 902653-01 |
Sheet 3 records a later ROM revision not shown elsewhere: UH1 as 6540-019 ROM (rev.), part 901439-09, or 2316B-09 ROM (rev.), part 901447-09.
Sheet 3 also gives the socket types, which matter when replacing one: 28-pin and 24-pin for UA2 and UH1–UH7 (the two ROM families are not the same pin count), 40-pin for UA5, UB8, UF3 and UG8, and 22-pin for the eighteen RAM positions.
What it does not contain
[edit | edit source]There is no voltage regulator in this list. The PET 2001 main logic board has none — it receives +5 V and +9 V unregulated from elsewhere in the machine. There is also no mains component, no reservoir capacitor and nothing to do with the monitor; all of that is on the display assembly, listed separately at Video Board Parts List (1 of 3).
One position is printed oddly. The LM555 timer is listed against ref. des. "UDE9", which is not a valid single location — the main logic schematic places the timer at E9. Read the board.
Related pages
[edit | edit source]- Commodore PET 2001 Service Documentation — the index to all of Commodore's PET 2001 documents held here
- Commodore PET 2001 Capacitor Replacement Guide — every figure on which comes from this list and its display-assembly counterpart
- Schematic 320026 (Complete, Board 320008) · Schematic 320082 (Complete, Board 320081) · Schematic 320130 (Complete, Board 320132) · Schematic 320135 (Complete, Board 320137)
Download: 2001_main_logic_assembly.pdf