Commodore V364 upgrades

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

For this system (exact model): The maker reports testing Diag264 on a V364. This is an exceptionally scarce unreleased prototype; use the non-invasive cartridge route and experienced 264-series service help rather than treating the ordinary KERNAL-replacement instructions as sufficient authority to open or modify it.

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.

CPLD replacements for failed PLA chips, currently sold for Commodore 264-series computers and previously made for the C64.

For this system (exact model): The seller explicitly names the prototype Commodore 364. Because surviving machines are exceptionally scarce, do not install it without model-specific confirmation and complete orientation and removal instructions.

The 264-series module exposed a login-or-register-to-buy path on 2026-07-27, while the separate C64 version is discontinued. Human review says the module plugs into the original socket, but the seller does not establish that every supported motherboard is socketed or document the original MOS part, board revisions, orientation, removal, or clearance. Treat it as a plug-in replacement only after confirming a compatible socket and orientation. A used C64 module needs the same checks.