Most computer projects begin by choosing a processor. The Homebrew CPU Ring begins by rejecting that shortcut.
Visit the Homebrew Computers Website
The rule is simple: a project belongs if the CPU itself was built rather than purchased as an off-the-shelf processor. It can imitate a commercial architecture, but the actual logic has to exist in real hardware. Simulations and paper designs do not qualify.
That leaves a wonderfully broad definition of “computer.”
The current index links machines built from TTL logic, relays, FPGA hardware, discrete components, and stranger approaches. Project names include Magic-1, Megaprocessor, TTLCPU, Pineapple One, Relay Computer, Home-Built TTL Computer, Gigatron, and many more.
The webring idea still makes sense here
This is one of the rare places where the old webring concept was almost perfect for the subject.
Each builder solved similar problems differently: instruction decoding, registers, clocks, arithmetic, memory interfaces, control logic, front panels, debugging, and physical construction. Following one machine naturally makes you curious about the next.
The site’s admission language even keeps some of the old-web personality: real hardware counts; simulations “don’t cut it :-).” The page also reminds visitors that the ring only links projects and that the intellectual property belongs to the individual builders.
That distinction matters because the value is distributed. There is no single canonical homebrew CPU. The archive is useful precisely because one person used relays, another built a bit-slice design, another recreated an 8080, and somebody else decided that a suitcase was a reasonable computer enclosure.
For students of digital logic, these projects expose processor architecture at a scale hidden by modern chips. A commercial CPU turns billions of transistors into a black package. A homebrew CPU turns the same ideas back into visible boards, wires, gates, lamps, and mistakes.
CacheRat found the ring while working through its broader 1,967-domain Ancient Web research list. Sites like this are why that list is more useful as a map than as a nostalgia dump.
You can learn a lot about CPUs by building one badly enough to see every part.