Delete comment from: Ken Shirriff's blog
Another MMI tidbit: the MMI PALs are programmed essentially the same as the MMI PROMs from the same era. Just the pinout is different. MMI was kind enough to publicly document the programming method for their fuse-based PROMs and PALs. I wish other companies did so - every one of them becomes defunct eventually, or their product becomes defunct, and the documentation is only preserved in the programming tool vendor R&D lab somewhere. Then the programming tool vendor becomes defunct, and the paper documentation and its facsimiles are gone. Then it takes to run an old programmer on some devices, with data capture set up to record the whole process to reverse-engineer it :(
Apr 28, 2025, 11:47:43 AM
Posted to Looking inside a 1970s PROM chip that stores data in microscopic fuses