// the find
rsc/unix
Old Unix programs running on modern computers.
A Go reimplementation of a PDP-11 CPU/instruction-set simulator plus a from-scratch port of the Research Unix Sixth Edition (V6) kernel logic that runs on top of it, with both a CLI and a browser-based front end. It's for people who want to actually run and poke at historical Unix internals, not just read about them.
The V6 kernel isn't just emulated hardware booting an old binary image — the kernel logic itself (syscalls, inode handling, pipes, signals) is rewritten in readable Go across files like sys1-4.go, inode.go, and pipe.go, which makes it genuinely useful for understanding how V6 worked rather than just running it as a black box. The PDP-11 core has real per-instruction test coverage (asm_test.go, exec_test.go) backed by dozens of golden test files for individual opcodes. There's near-zero friction to try it: `go run rsc.io/unix/v6run@latest` or a hosted web version at research.swtch.com/v6/.
No CI configuration is visible in the tree, so despite the test files there's nothing shown that enforces they stay green on changes. Documentation is thin — each subdirectory gets one paragraph in the README with no deeper writeup of which V6 kernel behaviors were deliberately simplified or dropped (it mentions skipping RK05 disk/terminal details but not what else diverges from a real V6 system). It's a single-maintainer project with no CONTRIBUTING.md and a small fork count, so don't expect much beyond personal exploration — there's no real 'adopt this in your stack' use case here, it's a study tool.