It was 50 years ago today, on October 31, 1974, that Federico Faggin, the mastermind behind the early Intel CPUs, left Intel to try something else. His next big thing was the Zilog Z-80 CPU.
Yet another Fairchild alumnus
Faggin, like the founders of Intel, previously worked at Fairchild. Faggin left Fairchild after Gordon Moore, Robert Noyce, and Andy Grove, coming to Intel in 1970. At Fairchild, he had been designing chips that used Silicon Gate Technology, and Fairchild wasn’t taking full advantage of the technology. He wanted to use SGT to design advanced new computer chips.
Faggin’s most famous work at Intel were the 4-bit 4004 and 4040 CPUs, and the 8-Bit 8008 and 8080 CPUs. The 8080 CPU saw widespread use in early kit and homebrew computers. The first ever Microsoft product ran on the 8080 CPU. So did the famous CP/M operating system.
Federico Faggin and the Zilog Z-80
Faggin’s next company, Zilog, was the first company to specialize in microprocessors. Its first product was the very famous Z-80 CPU, which took the 8080 in a somewhat different direction than Intel did with its followon 8085 CPU. The Z-80 was completely compatible with the 8080, but included numerous enhancements that made it especially well suited to creating home computers and game consoles with it.
It wasn’t long before the Z-80 became the preferred CPU for running CP/M, but it ended up in numerous other platforms as well. Sinclair used the Z-80 in its inexpensive home computers, as did Amstrad. This makes the Z-80 particularly beloved in the UK, since so many people grew up using Z-80-based microcomputers. The MSX architecture for home computers also used a Z-80 CPU. The Coleco Vision and Sega Master System game consoles also used it, and the Sega Genesis even utilized a Z-80 as a secondary coprocessor.
The popularity of 16- and 32-bit computers caused the Z-80 to wane in the mid to late 1980s, but it remained a very useful and popular niche CPU, not just for years, but for decades. The Z-80 was not discontinued until June 14, 2024. That’s a tremendous legacy.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.
