RIP Z80 CPU

Just days after I posted an article listing at least 5 brand new computers based on the Z80 CPU, I see this toot:

The notification

Z84C00 is the only CPU listed in the Classic products -> Z80 category of Zilog’s homepage.

If this is true, this would mark the end of almost 48 years of Z80 CPU life.

What’s NOT End of Life:

Important note: this does not suggest killing the successors: Z80N, eZ80, Z380, etc. just yet.

For example, eZ80, that remains in production, operates in Z80-compatible addressing mode (64 KB) or full 24-bit addressing mode (16 MB), and can be clocked at 50 MHz.

The hero – Z80 CPU

The Zilog Z80 microprocessor, introduced by startup company Zilog in July 1976, is a landmark in computing history warranted by its widespread adoption and enduring legacy. Designed by Federico Faggin and Masatoshi Shima, the Z80 emerged as a software-compatible extension of the Intel 8080, primarily targeting embedded systems. Its adaptability, however, led to its widespread use in desktop and home computers through the 1970s into the mid-1980s, and even in military applications, musical equipment, and arcade games.

Conception and Development

The Z80’s development journey began with Federico Faggin, who, after significant contributions to the Intel 4004 and 8080 microprocessors, decided to depart Intel to start his own company. Alongside Ralph Ungermann and later Masatoshi Shima, Faggin aimed to innovate beyond the limitations perceived at Intel. Initially considered a simple single-chip microcontroller due to financial constraints, the vision for Zilog’s first product evolved into a more sophisticated and complex microprocessor—the Z80. The Z80 aimed to offer compatibility with the 8080 while introducing advancements such as index registers and improved interrupts and was designed to stand out through economic feasibility and technical superiority.

Significance and Legacy

The Z80’s architectural innovation and operational enhancements over its predecessors made it a linchpin in the progression of computing hardware. Its affordable cost—about US $25 at launch—paired with its compelling features, led to its prevalence in a broad array of devices from the Osborne I, the first portable computer, to various home computers like the TRS-80 and MSX systems, and even in satellites. Zilog’s strategy of licensing the Z80 design to multiple manufacturers further cemented its global influence, enabling widespread acceptance and longevity in the market. Despite the advent of more powerful processors, the Z80’s influence persists, especially in embedded systems, due to Zilog’s pivot towards this market with products like the eZ80.

Drawing on robust design methodologies and tapping into a niche yet burgeoning market, the Z80 effectively disrupted the microprocessor industry, demonstrating the impact of innovation, strategic market positioning, and the significance of software compatibility in the evolution of computing hardware.

Best known computers using Z80

It’s impossible to name all of them (we can try though, for archival purposes), as there were hundreds of consumer machines on the commercial market alone that are based on Z80 or its derivatives.

Most notable home computers and consoles:

• Sega VIC Dual (1977)
• ColecoVision (1982)
• ZX Spectrum (1982 onwards)
• Camputers Lynx (1983)
• MSX (1983)
• Amstrad CPC (1984 onwards)
• MSX2 (1985)
• Elan Enterprise (1985)
• Sega Master System (1985)
• Nintendo Game Boy (1989)
• Sam Coupe (1989)
• Sega GameGear (1990)
• Nintendo Game Boy Colour (1998)
• RC2014 (2014)
• Spectrum NEXT (2020)
• Agon Light (2023)

List of CP/M-compatible Z80-based (or capable) systems

And if we wanted to see how widespread it is… the list of the Z80-based computers that additionally can also run CP/M operating system is over 230 items long!

Read more

• Zilog Z80 – Wikipedia
• Chip Hall of Fame: Zilog Z80 Microprocessor – IEEE Spectrum.
• How Two Bored 1970s Housewives Helped Create the PC Industry – a story behind the Vector Graphic computer