rejunity/z80-open-silicon
View on GitHub ↗ ★ 814 Verilog
Z80 open-source silicon clone. Goal is to become a silicon proven, pin compatible, open-source replacement for classic Z80.
12 mentions on Hacker News by 9 people: 3 stories, 9 comments · first 2024-04-21 · latest 2026-08-23
20082026
-
There are a number of efforts to make low volume production of compatible parts - see https://github.com/rejunity/z80-open-silicon There are also FPGA emulated versions.
comment by mithro · 2026-08-23 · in Z80 – The 1970s Microprocessor Still Alive (2021) -
There is a drop in compatible FOSS clone of Z80 https://github.com/rejunity/z80-open-silicon
comment by haunter · 2026-07-17 · in The Zilog Z80 has turned 50 -
FYI this how chip looks right now in the 5 mm^2 configuration. https://github.com/rejunity/z80-open-silicon/blob/main/docs/... The colourful lines in the middle are the metal wires (layers 2,3 & 4) displaying the interconnect inside the…
comment by __rej__ · 2025-12-15 · in Need chip art / logo for free and open source silicon clone of Z80 CPU -
…on the bottom part of Z letter? Would you mind submitting a ticket "issue" with it please?: https://github.com/rejunity/z80-open-silicon/issues PS: both PNG and SVG would be handy.
comment by __rej__ · 2025-12-15 · in Need chip art / logo for free and open source silicon clone of Z80 CPU -
…on making a drop-in replacement for the Z80, as open source and free silicon. Git repo is here. https://github.com/rejunity/z80-open-silicon
comment by ethanholt1 · 2024-04-30 · in Z80 is dead – The chip that changed my world – and yours -
…it's even doing a switch-case over the opcode, which is very typical for a software CPU emulator: https://github.com/rejunity/z80-open-silicon/blob/974c7711b2... Instruction decoding on a real Z80 CPU doesn't work at all like that :) A…
comment by flohofwoe · 2024-04-28 · in Zilog Z80 CPU – Modern, free and open source silicon clone -
…rate and alternates between control signals, A0-A7, control signals, and A8-A15 on the OUT pins: https://github.com/rejunity/z80-open-silicon/blob/68438f0019... So you'd get an effective 12.5MHz Z80 clock and need a bit of external logic…
comment by swetland · 2024-04-28 · in Zilog Z80 CPU – Modern, free and open source silicon clone -
…the original Z80 "transistor layout"). For instance here's the LD A,(DE) "instruction payload": https://github.com/rejunity/z80-open-silicon/blob/974c7711b2... And here's the same machine cycle in my software emulator:…
comment by flohofwoe · 2024-04-28 · in Zilog Z80 CPU – Modern, free and open source silicon clone -
This page says 50 MHz. https://github.com/rejunity/z80-open-silicon/blob/main/docs/...
comment by drmpeg · 2024-04-28 · in Zilog Z80 CPU – Modern, free and open source silicon clone