Replacement of some old prom by a GAL, Application to a Thaler MPS-65 board

Didier form was approached by his friend Erik about a malfunctioning MPS-65.

By studying the material on this page and doing measurements on the board it was decided the PROM on the board was malfunctioning.

So Didier designed a GAL replacement for the PROM and the board came back to life!

Here the story how the design looks like.