Article here on the Fairchild Sentry
The tester had removable panels and two doors that could swing open. Each door held three banks of cards of TTL and ECL logic, with a five-foot-tall, wire-wrapped backplane. I once tried to count the ICs in the tester and came up with a number — around 60,000 chips.
If you used a Z80 chip back in the 1980s, it almost certainly passed through a single room and its Fairchild Sentry 610 test system. Mostek had grown into the one’s top producer of DRAM, and every Z80 microprocessor — including Zilog-branded ones — went through tests there.
Several MTSI engineers began their careers at Mostek which invented the multiplexed DRAM, too. But back in 1971, Mostek’s engineers were introduced to the Sentry 610. Fairchild Systems had just introduced the first computer-controlled, modularized, expandable test system product line in the the Sentry series. These third-generation systems were designed to test complex MSI/ LSI integrated circuits, electronic subsystems, and systems.
(When I worked for Plessey in the early 80’s, there was certainly talk of very expensive ATEs (Automated Test Equipement) - I vaguely recall price tag of a million. The designs I worked on didn’t have any DFT (Design For Test) features, I think, so the test programs would all be hand-crafted and probably low coverage. My next employer was Inmos, where they’d built their own Transputer-based test equipment, called TTTE, popularly back-formed as Thomas The Tank Engine)
via this discussion on HN