Tag: ram test

5 matching upgrades

Showing 5 products.

StatusProductWhat it doesCompatibilityLinks
AvailableChecked Jul 30, 2026C64 781220 Dead Test Cartridgeby Commodore service ROM; current build by Retro Rewind

Boots before the normal KERNAL to diagnose RAM and ROM faults on a Commodore 64 that cannot reach its startup screen.

Retro Rewind listed its cartridge in stock at CAD 22 on 2026-07-30. TFW8b documented a compatible alternative for C64, C64C, SX-64, and C128 in 64 mode, but that listing was out of stock. Wait up to 60 seconds for a result. The original 781220 RAM routine covers only the lowest 4 KB, and the cartridge does not test the chips and I/O covered by a harness kit.

Sources
  • Commodore 64 Exact model
  • Commodore SX-64 Exact model
  • Commodore 128 Exact model
AvailableChecked Jul 30, 2026C64/C128 586220 Diagnostic Harness Familyby Sven Petersen and Commodore service design; assembled by several sellers

Adds the loopback modules needed for complete 586220 C64 or 785260 C128 port and interface diagnostics.

Current routes on 2026-07-30 included Retro-Updates' EUR 17.95 harness with an Add to Cart path, Retro Rewind's CAD 75 harness with a one- to two-week lead time, Retro Rewind's separate CAD 22 C128 keyboard dongle in stock, and AMI64's GBP 49 complete eight-ROM kit. Retro Electronics had one complete kit on 2026-07-25 but documented only one tested PAL C64 board revision. Confirm the exact harness revision, cartridge, keyboard dongle, cable lengths, model settings, and included manuals before ordering. Human review found no evidence that the current retail dongle solves the documented C128DCR keyboard-jack power conflict.

Sources
  • Commodore 64 Exact model
  • Commodore 128 Exact model
  • Commodore SX-64 Exact model
AvailableChecked Jul 24, 2026Dead Test Switcher for Apple IIby Infinity Products and kerokero5150

Switches an Apple II F8 ROM socket between its normal Auto-Start Monitor and a licensed RAM diagnostic ROM.

The current Infinity Products page listed an assembled product without an out-of-stock marker on 2026-07-24. Personal-use fabrication files remain available under a noncommercial license; the Dead Test ROM has separate licensing terms.

Sources
  • Apple II Exact model
  • Apple II Plus Exact model
Build itChecked Jul 30, 2026Diag264 Diagnostic ROM and Harnessby Rob Clarke, with OpenC16Cart hardware by SukkoPera

DIY diagnostic ROM and loopback harness for PAL and NTSC Commodore 264-family computers.

Rob Clarke's current download directory offered Diag264 0.97 on 2026-07-30. The maker also offers a programmed EPROM at media and postage cost by email. The software is CC BY-NC-ND 4.0: unmodified personal distribution with attribution is allowed, but modification and commercial resale are prohibited. The maker warns that some third-party marketplace copies were unauthorized or modified. Loopback hardware may be resold when the attribution conditions are met.

Sources
  • Commodore 16 Exact model
  • Commodore 116 Exact model
  • Commodore Plus/4 Exact model
  • Commodore V364 Exact model
Find usedChecked Jul 30, 2026HES MON 64by Human Engineered Software (HES)

Vintage C64 machine-language monitor cartridge with assembly, debugging, memory, and relocation tools.

ConsoleMAD listed one original cartridge-only unit at GBP 24 on 2026-07-30; it was missing its label. RavenWolf's tested USD 12 cartridge was sold out and had been recovered from a workshop with harsh long-term storage conditions. Treat every offer as an individual used item. The HES software and manual remain copyrighted, so this record does not present an unlicensed ROM download as a DIY route.

Sources
  • Commodore 64 Exact model