This page catalogues all known Commodore diagnostic cartridges (and plug-in diagnostic boards) released for 8-bit Commodore computers—from the PET series through the 264 family—and includes modern re-creations and multi-ROM compilations.
Disk-based test suites, cable harnesses, and routine “loop-back plugs” are 'out of scope.
Commodore PET / CBM 2000-8000 series
| Cartridge / Board |
Part No. / ROM Rev |
Era |
Year |
Supported models |
Notes
|
| PET Service Diagnostic Board |
320345-01 |
Original |
1979 |
PET 2001/3xxx/4xxx/8xxx |
6502 daughter-board supplied to Commodore service depots
|
| PET “ROM-RAM” Diagnostic Board |
— |
Original |
1981 |
PET 2001-N → 4032 |
Replaces system ROM/RAM; displays fault map
|
| PET Diagnostic Clip (Tynemouth) |
— |
Modern |
2016 |
PET 2001-8032 |
CPU-socket clip with self-contained ROM test suite
|
Commodore VIC-20
| Cartridge |
Part No. / ROM Rev |
Era |
Year |
Supported models |
Notes
|
| VIC-20 Diagnostic Cartridge |
324503-01 |
Original |
1982 |
VIC-20 |
Official Commodore service cartridge
|
| VIC-20 Dead Test Cartridge |
— |
Modern |
2021 |
VIC-20 (PAL & NTSC) |
Starts with bad-RAM bypass; useful when VIC shows black-screen
|
| VIC Audio/Video/Keyboard Test Cart |
— |
Modern |
2023 |
VIC-20 (unexpanded) |
Community utility for colour-bar, sound and matrix tests
|
Commodore 64 / SX-64
| Cartridge |
Part No. / ROM Rev |
Era |
Year |
Supported models |
Notes
|
| C64 Diagnostic Cartridge Rev 326070 |
326070-01 |
Original |
1982 |
C64 revision A boards |
First-generation diagnostic; no user-port tests
|
| C64 Diagnostic Cartridge Rev 586220 |
586220-01 |
Original |
1984 |
All C64 / SX-64 |
Standard service cartridge used with harness
|
| C64 Dead Test Cartridge Rev 781220 |
781220-01 |
Original |
1988 |
C64 / C64C / SX-64 |
Boots with minimal RAM; flashes error codes
|
| C64 Diagnostic Cartridge Rev 785260 |
785260-01 |
Original |
1992 |
Late C64C boards |
Adds CIA timer check; harness unchanged
|
| Dual Dead-Test & Diagnostic (2-in-1) |
— |
Modern |
2015 |
C64 / C128 (64-mode) |
DIP-switch selects 781220 or 586220 ROM
|
| DIAGcart 64 (4-in-1) |
— |
Modern |
2022 |
C64 / SX-64 |
Contains 781220, 586220, 586220+ and RAM-only tests
|
| MultiROM Diagnostic (586220 + 785260) |
— |
Modern |
2021 |
C64 / C64C |
Menu-driven multi-revision cartridge
|
Commodore 128
| Cartridge |
Part No. / ROM Rev |
Era |
Year |
Supported models |
Notes
|
| C128 Diagnostic Cartridge Rev 789010 |
789010-01 |
Original |
1985 |
C128 / C128D |
40-column mode; requires harness
|
| C128 Diagnostic Cartridge Rev 588121 |
588121-01 |
Original |
1987 |
C128 / C128D |
Updated ROM; tests MMU & VDC pointers
|
| C128 Dual-Diag (Cartridge) |
— |
Modern |
2021 |
C128 / C128D |
Selectable 789010 or 588121 images
|
Commodore 264 family (C16 / Plus/4 / C116)
| Cartridge |
Part No. / ROM Rev |
Era |
Year |
Supported models |
Notes
|
| Commodore TED Diagnostic (service) |
318004-01 |
Original |
1984 |
C16 prototype boards |
Factory-only ROM; rare
|
| Diag264 |
v0.97 |
Modern |
2012 |
C16 / Plus/4 / 116 |
Community open-source diagnostic; PAL & NTSC
|
| Diag264 Cartridge + Harness kit |
— |
Modern |
2020 |
C16 / Plus/4 / 116 |
Gold-finger PCB and full loop-back set
|
