The Zilog Z80 8-bit microprocessor marks its 50th anniversary this month, having first shipped in July 1976. Over five decades it powered home computers, industrial controllers, and arcade machines, and hobbyist David Oberhollenzer marked the occasion with a personal retrospective.

The anniversary is bittersweet: Littelfuse, which now owns Zilog, announced in 2024 that it would discontinue the standalone Z80 processor and its peripheral chips, ending official production of the chip shortly before this milestone.

Retirement hasn't ended the Z80's community. Enthusiasts have kept building for it, including new operating systems, a NASM-inspired SDK-style development toolchain, and demonstrations of multitasking on the original hardware. The architecture also survives commercially in derivatives such as the eZ80 system-on-chip used in Texas Instruments' TI-84 Plus CE calculator, which one hobbyist used as the target for a port of Sonic 2, originally written for the Z80-based Sega Master System.

Not every Z80 project succeeded: Zilog's own operating system for the chip, Z80-RIO, never gained the traction of the hardware itself. Commenters on the retrospective noted that the Z80 launched at $25 in 1976 — about $145 in 2026 money — a fraction of what advanced processors cost today.