Schematic 320082 (Sheet 2 of 3, Board 320081)

Commodore drawing #320082, sheet 2 of 3, titled PET Computer Main Logic — Memory Section and subtitled "pertaining to board assembly #320081". Commodore Business Machines, Inc., Palo Alto, California.

This is the ROM and RAM array of the static Commodore PET 2001 board fitted with 2316B ROMs and 6550 RAM. It is the memory half of what distinguishes the four original board assemblies from one another — sheet 1 of every set is the same universal drawing, Schematic 320130 (Sheet 1 of 3, Static PET).

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.

Board assembly ROMs RAM Drawing number for sheets 2–3
320008 6540 6550 320026
320081 2316B 6550 320082
320132 6540 2114 320130
320137 2316B 2114 320135

Circuits marked with an asterisk on this sheet are annotated "all ckts marked * are for BC machine only" — the business-keyboard variant.

This drawing carries no parts list. For component values and Commodore part numbers see System Board Parts List (1 of 3); for the machine's power supply and monitor, which are a separate assembly entirely, see Video Board Schematic.

The same sheet is page 2 of the complete set at Schematic 320082 (Complete, Board 320081), which is the better link to cite if you want all three sheets together. This page holds the higher-resolution scan of this sheet on its own.

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Commodore drawing 320082, sheet 2 of 3 — PET Computer Main Logic, Memory Section, board assembly 320081.

Download: 320081-2.gif