Zilog Z80: Ex-Intel Engineers, Exxon Money and a 48-Year Production Run

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

Federico Faggin and Ralph Ungermann left Intel in 1974, and Masatoshi Shima joined them the next year. Funded by Exxon's computing division, they named the company Zilog, for Z Integrated Logic, with Z meant as the last word in logic. The Z80, released in 1976, ran Intel 8080 code but added a larger instruction set, a built-in DRAM refresh controller and a single 5-volt supply instead of three. It powered the Sinclair ZX Spectrum and Tandy TRS-80, became the base for CP/M and software like WordStar and dBase, and filled arcade cabinets: Pac-Man used one, Scramble two and Galaga three. Sega used it in the Master System and Game Gear and as the Genesis sound processor, and it ran Texas Instruments graphing calculators.

The 16-bit Z8000 of 1979 dropped Z80 compatibility and lost ground to Intel's x86. Ungermann left in 1978, Exxon took full ownership in 1980, and CEO Edgar Sack led a 1989 management and employee buyback, with a public listing in 1991. Texas Pacific Group bought Zilog for $527 million in 1998, CEO Curtis Crawford borrowed to chase 32-bit data communications chips, and the company filed for Chapter 11 in late 2001. Under Jim Thorburn it refocused on embedded microcontrollers, sold its ARM9 line to Maxim and its remote control unit for $31 million, and was bought by IXYS for $62.4 million in 2009. Littelfuse acquired IXYS for $750 million in 2017.

• Zilog marketed the Z8000 with a superhero comic book called Captain Zilog.
• The Commodore 128 and DEC Rainbow 100 carried a Z80 beside their main processor just to run CP/M software.
• The Zilog SCC serial controller became standard in early Apple Macintosh computers and Sun SPARCstations.
• When NXP abandoned 8051 microcontrollers, Zilog released its own 8051 family to pick up stranded customers.
• The original Z80 was discontinued in 2024 after 48 years in continuous production.