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Auto-created Commodore PET 2001 schematic page
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P4 verification: real documentation page โ€” identifies the sheet from its own title block, records that sheet 1 of every set is drawing 320130, and links the parts lists and display-assembly documents
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'''Commodore drawing #320082''', the complete three-sheet main logic schematic for '''PET 2001 board assembly #320081''', Commodore Business Machines, Inc., Palo Alto, California. Three A-size sheets, scanned at 400 dpi.
Assembly 320081 is the static PET 2001 board fitted with '''2316B ROMs and 6550 RAM'''.
== The three sheets ==
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table"
|-
! Sheet !! Drawing number in the title block !! Title !! Also on this wiki as
|-
| 1 of 3 || '''#320130''' โ€” not #320082 || ''PET Computer Main Logic'' โ€” "Circuitry common to all PET computers" || [[Schematic 320130 (Sheet 1 of 3, Static PET)]]
|-
| 2 of 3 || #320082 || ''PET Computer Main Logic โ€” Memory Section'', pertaining to board assembly #320081 || [[Schematic 320082 (Sheet 2 of 3, Board 320081)]]
|-
| 3 of 3 || #320082 || ''PET Computer Main Logic โ€” Video Logic'', pertaining to board assembly #320081 || [[Schematic 320082 (Sheet 3 of 3, Board 320081)]]
|}
'''Sheet 1 is the same drawing in all four sets.''' Its title block reads #320130 whichever board's PDF you open, which is why this wiki holds only one copy of it. Sheets 2 and 3 are the board-specific drawings and carry #320082.
== The four static board assemblies ==
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table"
|-
! Board assembly !! ROMs !! RAM !! Drawing number for sheets 2โ€“3
|-
| 320008 || 6540 || 6550 || 320026
|-
| 320081 || 2316B || 6550 || 320082
|-
| 320132 || 6540 || 2114 || 320130
|-
| 320137 || 2316B || 2114 || 320135
|}
Commodore's note is printed on sheets 2 and 3 of every set: '''"All locations are same on all boards; only the specific components will differ on boards numbered 320132, 320081, 320137, 320008. The identifying board number is in upper left corner."''' So a component location read off one of these drawings is valid for any static PET 2001 board; only the fitted part changes.
== What these sheets contain ==
* '''Sheet 1''' โ€” the 6502 at UF3, both 6520 PIAs (UB8, UG8), the 6522 VIA (UA5), the three MC3446 IEEE-488 transceivers at UA7โ€“UA9, the LM555 retrace timer, the cassette interface with its TIP29 motor drivers and 7.2 V zeners, and the keyboard matrix pull-ups. '''No regulator''' โ€” the board takes +5 V and +9 V unregulated from elsewhere in the machine.
* '''Sheet 2, Memory Section''' โ€” the ROM and RAM array for this assembly specifically, which is what distinguishes the four boards.
* '''Sheet 3, Video Logic''' โ€” character generator, video timing and the display output.
Some circuits on sheets 2 and 3 are marked with an asterisk and annotated '''"all ckts marked * are for BC machine only"''' โ€” the business-keyboard variant.
== What these sheets do not contain ==
* '''No parts list.''' Values appear on the drawing where the drawing carries them. For the full component list with Commodore part numbers see [[System Board Parts List (1 of 3)]] and [[Commodore PET 2001 Service Documentation]].
* '''No power supply and no display circuitry.''' The mains transformer, the rectifiers, the 4700 ยตF reservoir and the flyback are all on the '''display assembly''' โ€” see [[Video Board Schematic]] and [[Video Board Parts List (1 of 3)]].
Each sheet carries Commodore's 1970s trade-secret notice down the left edge. It is of historical interest only.
== Related pages ==
* [[Commodore PET 2001]] ยท [[Commodore PET 2001 Service Documentation]] ยท [[Commodore PET 2001 Capacitor Replacement Guide]] ยท [[Commodore PET 2001 General Maintenance]] ยท [[Commodore PET 2001 Troubleshooting]]
* The other three board sets: [[Schematic 320026 (Complete, Board 320008)]] ยท [[Schematic 320130 (Complete, Board 320132)]] ยท [[Schematic 320135 (Complete, Board 320137)]]
<pdf> File:320081.pdf </pdf>
<pdf> File:320081.pdf </pdf>


Download the file here: [[:File:320081.pdf|320081.pdf]]
Download: [[:File:320081.pdf|320081.pdf]]


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

Latest revision as of 02:05, 25 September 2026

Commodore drawing #320082, the complete three-sheet main logic schematic for PET 2001 board assembly #320081, Commodore Business Machines, Inc., Palo Alto, California. Three A-size sheets, scanned at 400 dpi.

Assembly 320081 is the static PET 2001 board fitted with 2316B ROMs and 6550 RAM.

The three sheets

[edit | edit source]
Sheet Drawing number in the title block Title Also on this wiki as
1 of 3 #320130 โ€” not #320082 PET Computer Main Logic โ€” "Circuitry common to all PET computers" Schematic 320130 (Sheet 1 of 3, Static PET)
2 of 3 #320082 PET Computer Main Logic โ€” Memory Section, pertaining to board assembly #320081 Schematic 320082 (Sheet 2 of 3, Board 320081)
3 of 3 #320082 PET Computer Main Logic โ€” Video Logic, pertaining to board assembly #320081 Schematic 320082 (Sheet 3 of 3, Board 320081)

Sheet 1 is the same drawing in all four sets. Its title block reads #320130 whichever board's PDF you open, which is why this wiki holds only one copy of it. Sheets 2 and 3 are the board-specific drawings and carry #320082.

The four static board assemblies

[edit | edit source]
Board assembly ROMs RAM Drawing number for sheets 2โ€“3
320008 6540 6550 320026
320081 2316B 6550 320082
320132 6540 2114 320130
320137 2316B 2114 320135

Commodore's note is printed on sheets 2 and 3 of every set: "All locations are same on all boards; only the specific components will differ on boards numbered 320132, 320081, 320137, 320008. The identifying board number is in upper left corner." So a component location read off one of these drawings is valid for any static PET 2001 board; only the fitted part changes.

What these sheets contain

[edit | edit source]
  • Sheet 1 โ€” the 6502 at UF3, both 6520 PIAs (UB8, UG8), the 6522 VIA (UA5), the three MC3446 IEEE-488 transceivers at UA7โ€“UA9, the LM555 retrace timer, the cassette interface with its TIP29 motor drivers and 7.2 V zeners, and the keyboard matrix pull-ups. No regulator โ€” the board takes +5 V and +9 V unregulated from elsewhere in the machine.
  • Sheet 2, Memory Section โ€” the ROM and RAM array for this assembly specifically, which is what distinguishes the four boards.
  • Sheet 3, Video Logic โ€” character generator, video timing and the display output.

Some circuits on sheets 2 and 3 are marked with an asterisk and annotated "all ckts marked * are for BC machine only" โ€” the business-keyboard variant.

What these sheets do not contain

[edit | edit source]

Each sheet carries Commodore's 1970s trade-secret notice down the left edge. It is of historical interest only.

[edit | edit source]

Download: 320081.pdf