Zilog Z80: the chip that made computer history turns 50. And it's about to be reborn

The Zilog Z80 has turned 50 years old. The 8-bit processor, which debuted on the market in July 1976, remained in production for 48 years, until Zilog, now controlled by Littelfuse, ceased to accept orders in 2024. However, an open-source clone, created entirely by the community, promises to bring the chip back to life in its historic DIP40 40-pin package.

The original project housed 8,500 transistors on a 4-micron production process, with a typical operating frequency of 2.5 MHz, which subsequent CMOS variants pushed up to 20 MHz. Its binary compatibility with the Intel 8080 allowed it to inherit the entire software library written for CP/M, while the integrated DRAM refresh counter directly within the chip reduced the number of supporting components needed around the processor. Upon its debut, it cost $25, approximately $145 adjusted for the purchasing power of 2026.

The Z80 powered the ZX Spectrum, the TRS-80, MSX machines, Nintendo's Game Boy, Sega's Master System, and the Pac-Man arcade cabinet, as well as Texas Instruments graphic calculators. It continued to operate for decades within industrial controllers, well beyond the point when home computing moved to more powerful architectures. The end-of-life communication, dated April 15, 2024, informed customers that the wafer foundry used by Zilog was discontinuing support for the Z84C00 family, with the last orders closing in June of the same year.

The open-source clone aims for DIP40

To carry on the legacy of the chip, the FOSS Z80 project by Renaldas Zioma kicked off immediately after the announcement of the end of production and has already reached functional silicon. The first version, made on the SkyWater 130-nanometer process via the Tiny Tapeout 7 program, occupies a die of just 0.064 square millimeters and has been confirmed to be functional through the project's repository.

A QFN64 variant with all 40 pins exposed followed, made on the Efabless CI2406 shuttle, along with two other iterations on the 130-nanometer process from IHP. The latest ongoing phase is instead focusing on the classic DIP40 format, with a chip-on-board assembly on the GlobalFoundries 180-nanometer GF180MCU node via Wafer.Space: the aim is to achieve a pin-compatible replacement for machines like the ZX Spectrum and RC2014 kits.

The project is based on the TV80 Verilog core developed by Guy Hutchison, and the 130-nanometer implementation is expected to support frequencies up to 50 MHz, compared to the 4 MHz of the original NMOS piece.

Meanwhile, Zilog is also reducing the range of official successors to the Z80. A product change communication issued last October put the eZ80L92 and several microcontrollers from the Z8F series end-of-life, citing “minimal or no demand.” The last orders closed on January 20, 2026, with final deliveries expected by April 20, on non-cancellable and non-returnable terms. The eZ80 architecture, introduced in 2001 and still present in TI-84 Plus CE calculators, remains in Zilog's catalog.