Hi VOGONS,

Long-time lurker, finally registered. Andreas from Switzerland — I've spent some time staring at vintage boards trying to find the one flaky ZIP RAM among sixteen identical ones to do something about it.

After spending 100+h, the result is a small standalone RAM tester with OLED display and ZIF socket. It currently handles 4027, 4116/4816, 4416, 4164, 4464, 41256, 44256 and 411000/514400 (incl. static-column and nibble-mode variants), plus the awkward "half-good" 32Kx1 parts (TMS4532 / MSM3732) with quadrant detection since FW 4.2.3. Most 4-Bit types also work in 20-pin ZIP packages. Hardware and firmware are GPL — sources and the PCBWay shared project links for through-hole builders are on the repository.

The project has also been covered by Hackaday and Elektor. For those who prefer not to build it themselves, links to pre-assembled units are listed on GitHub as well.

GitHub: https://github.com/tops4u/Ram-Tester

Looking forward to hearing what you think about it, or what features you miss.

Andreas
(handle: tops4u)