Editing 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.''' <code>2001_main_logic_assembly.pdf</code> 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 ==
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table"
|-
! 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 ==
'''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 ==
* [[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)]]

<pdf> File:2001_main_logic_assembly.pdf </pdf>

Download: [[:File:2001_main_logic_assembly.pdf|2001_main_logic_assembly.pdf]]

[[Category:Commodore PET 2001 Schematics]]
[[Category:Commodore Documentation]]