Hub · Featured homebrew · Curated directory · Sep 2026
Federico Faggin’s Zilog Z80 (1976) extended the Intel 8080 with more registers, a richer instruction set, and a friendlier bus — then rode the home-computer and CP/M waves for decades. Spectrums, TRS-80s, MSX, Game Boys, arcade boards, and industrial controllers kept it alive; today a lively homebrew scene still boots CP/M from SD cards and teaches kids how an 8-bit bus feels. This desk collects two featured modern builds and a large directory of docs, OS archives, SBCs, and tools — link-outs only, no copyrighted manuals pasted wholesale.
Why the Z80 still matters
CP/M made the Z80 the business CPU of the late seventies: editors, compilers, and bulletin-board culture ran on banked 64 KB machines with floppy “drives.” Home micros (ZX Spectrum, Amstrad CPC, MSX, TRS-80, Sharp MZ, many others) made assembly and BASIC a living room skill. Soft cores, CPLD glue, and cheap flash keep the same instruction set reachable with a soldering iron and a serial terminal.
For computer-history and electronics desks, the Z80 is a sweet spot: complex enough to teach paging, interrupts, and peripherals; simple enough that a through-hole SBC still fits a 100×100 mm board.
Featured first
Two modern projects Steven wanted on top: an all through-hole American CP/M SBC with video lessons, and a Chinese modular educational computer that runs CP/M and SG-1000 games.
Featured · Through-hole SBC · CP/M 2.2
John Winans — Z80 Retro!
A 100×100 mm all through-hole single-board computer: Z80, 512 KB SRAM, FLASH ROM, serial and parallel I/O, SD card storage, and a companion Raspberry Pi FLASH programmer. Designed so anyone who can solder through-hole parts can bring up CP/M 2.2 from scratch. John’s Basement playlist walks the build and BIOS.
立创开源 / OSHWHub project by ayssn — a hand-built modular 8-bit computer (手搓8位计算机 Z80-V2) aimed at students and makers. Motherboard plus LED array, VDP graphics, PSG/joypad, CF storage, PS/2 keyboard, and serial. Runs CP/M and 32 KB SG-1000 games. Treat this as the flagship modern “Chinese kids / classroom education” Z80 build.
Classroom history (China). The VTech Laser 310 / VZ200 family (Z80A) was widely used in mainland primary and secondary schools and Children’s Palaces in the 1980s–90s. The 中华学习机 CEC-I (China Educational Computer) was a popular kids’ machine of the same era — but it is a 6502 / Apple II–compatible design, not a Z80. Laser 310 is the Z80 school machine; CEC is the cousin for context, not the same CPU.
Grab everything — curated directory
Scannable links with one-line blurbs. Prefer working URLs; a few classic hosts are HTTP-only or historically flaky — marked where known.
Core docs & portals
z80.info — Thomas ScherrerThe long-running Z80 portal: manuals, opcode notes, emulators, links. Prefer http:// if https fails.
Bitchin100TRS-80 Model 100 / portable Kyoto clan — related 8085/Z80-era culture.
OldComputers.netMuseum-style catalog of vintage micros including many Z80 machines.
Opcode overview (link-out)
The Z80 is an 8080-compatible core plus IX/IY, alternate register set, block moves, and bit ops. Do not paste copyrighted manuals here — use the free tables and vendor PDFs above.
Main map
Single-byte opcodes cover 8080-style loads, ALU, jumps, calls, and restarts. Undocumented shifts (SLL) and combinations exist; emulators disagree on edge cases — prefer tested cores.
Prefixes
CB bit/rotate on registers or (HL). ED block transfer, I/O, and extras. DD/FD select IX/IY. Double prefixes (DDCB / FDCB) index bit ops with a displacement.
Timing
Count T-states (clock ticks) and M-cycles. DRAM refresh steals cycles on M1. Homebrew clocks often 4–10 MHz; peripherals (SIO/CTC) want clean mode-2 interrupt daisy chains.
Educational link desk — not a substitute for datasheets, license terms, or the projects’ own READMEs. CP/M redistribution follows the clarified Digital Research terms collected on cpm.z80.de; always check the source you download. Outbound sites change; if a link 404s, start from z80.info or the project’s org page.