Designed by Federico Faggin's Zilog, the Z80 was an 8-bit CPU compatible with the Intel 8080 but with more registers and instructions — and it became one of the longest-lived processors ever. It ran CP/M computers, countless arcade boards, the Master System, the Game Gear, and the MSX standard.
The Four Natures
each piece emerges by one of four natures
The Idea
the three-beat story
The Z80 runs Intel 8080 software but adds an alternate register set, index registers, and new instructions — more capable, and easy to adopt for anyone already on the 8080. A smart, compatible upgrade.
It became the standard CPU of CP/M business computers and a workhorse of the arcade era, then powered the MSX home-computer standard — ubiquitous through the late 70s and 80s.
Sega's Master System and Game Gear ran on the Z80, and the Game Boy used a closely related custom core. Remarkably, Z80-family chips stayed in production for decades — one of the most enduring designs in computing.
The Teardown — Click a Block
the machine, laid out as a block diagram — the main processor on top, the rest of the silicon beneath, buses showing what talks to what. Click any block to read its spec. An accurate architecture diagram (a teardown illustration, not a schematic).
The Spec Sheet
the headline numbers — the spec edition
Zilog · 1976.
plus extensions.
index registers.
Master System · Game Gear.
extraordinarily long-lived.
The Reckoning
the teardown, and the honesty about it
The Domain: Open It and Spec It
the teardown
- EXEREÚNESIS takes a real, made machine apart down to the chip and writes the honest spec — not a story-world but a technical anatomy.
- >One of a growing series of console teardowns; siblings link from the marquee.
Two-Layer Honest
datasheet vs lore
- Settled: the Z80's 8080 compatibility, extended registers, and use across CP/M, the MSX, arcades, and Sega's 8-bit consoles are documented.
- Flagged: the Game Boy used a custom Z80/8080-like core (the Sharp LR35902), not a stock Z80 — clarified, since the two are often conflated.
Render, Not Invent
sourced
- Summarized from the public technical record for the THE ZILOG Z80; the manufacturer and its engineers are cited, not minted.
- No ROMs, BIOS, or copyrighted code are reproduced. Emergents are physical components; the block diagram is an illustration, not a schematic.
The Roster
every chip and part as an ACI .agent — each a birth certificate & a nature (6)
