A bit of Z80 history

Actually, more on the testing machine used for the Z80 and other chips. From 2021. Via Hacker News.

If you used a Z80 chip back in the 1980’s, it almost certainly passed through this room. This photo is of the first Fairchild Sentry 610 test system at Mostek We tested every Z80 chip including Zilog branded ones in this room for many years. (photo from Mostek 1973 databook). We also tested Fairchild F-8 CPU chips, and exotic parts such as the Magnavox “Star” TV tuner chips. It was general purpose and could test RAMs, calculators, and ROMS, though we made our own custom testers for those. This room pretty much did all the heavy lifting on all the early CPU chips. Mostek had a second source license for many of the the popular CPU chips – the Fairchild F-8 series, the Z80, the Intel 8088/6, and the Motorola 68000 family. And we invented the multiplexed DRAM, too.

Image of the tester from the post.


Interesting to learn about a side of chip making that I haven’t heard much about. I really like hearing about the various problems encountered. So often history boils away the screw-ups and dead-ends making current day events look so disorganized and chaotic.