The CommonPET is a 100% compatible replica of the SuperPet combo board for PET/CBM 8032 computers from 1981. It implements all the features, including the 64K RAM addon, compatibility for the OS9 MMU well as the support for the internal RS-232 connector.

Most of the components are readily available. Chips not available from Mouser or Digikey can still be purchased as NOS from a variety of sources.

Schematic

Bill of Materials

The Firmware of the SuperPET is available at zimmers.net: http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/pet/SuperPET/index.html

UA3: characters.901640-01.bin (PETside CharROM):

U47: waterloo-a000-bfff.970018-12.bin

U48: waterloo-c000-dfff.970019-12.bin

U49: waterloo-e000-ffff-970034-12.bin (50Hz Version)

U49: waterloo-e000-ffff.970020-12.bin (60Hz Version)

Adapters to use 2764 EPROM work, 27hc641 that are programmed to be pin compatible to 2364 are recommended.

CBM in its infinite wisdom only provided +5V and -9V for the 1488 line driver. A low voltage 1488E or 14C88 is recommended.

A replica of the OS/9 addon board can be found in the os9_mmu folder

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
See https://creativecommons.org/licenses/by-sa/4.0/.

This work would not have been possible without the help from a bunch of amazing people from VzEkC e. V. forums. Many thanks go out to:

• for(;;) - for creating the amazing µMMF project that inspired this work
• vossi - for providing excellent images of a ASSY 324100 board
• CBM_Ba and Richi- for building and testing the first prototype

Special credits go out to Mike Naberezny for researching the OS/9 MMU schematics