Tag: loopback test

Tests major Commodore 64 chips, ROMs, interrupts, controls, and external ports with a cartridge and loopback plugs.

Protovision announced that 64 Doctor was back in stock on 2026-07-21. The product page listed eight units at EUR 35 with a one- to two-week shipping estimate on 2026-07-30. A detailed 2019 review identifies Tim Harris of Shareware Plus as the licensed manufacturer and demonstrates the test sequence, but it does not establish equivalent sound-test behavior for an 8580 or replacement SID, the SX-64, or a C128 in C64 mode.

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.

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.

Tests a VIC-20's keyboard, IEC, user, cassette, and joystick interfaces with a machine-specific cartridge and loopback harness.

AMI64 listed its GBP 47 complete cartridge-and-harness kit as available in around ten days on 2026-07-30. CMD Marketplace listed three USD 59.90 PAL/NTSC kits, but its Tindie page exposed conflicting United States shipping text and no usable US rate. Sven Petersen publishes the GPLv3 hardware and firmware project.