This looks awesome. The readme says it's unsure if this is v6 or v7. Diff of a few files suggests v6 with the 'u' area being a pointer instead of a struct and a few of the elements names changed a bit... The dates are from 1976 or 1977, which also matches...

And we have this from wikipedia: "By 1976, the operating system was in use at various academic institutions, including Princeton, where Tom Lyon and others ported it to the S/370, to run as a guest OS under VM/370."  which matches the dates as well found on the tape.

This is seriously cool. There are a few corrupted files (like dsk.h). Kernel sources are there, but there's no userland programs apart from the assembler and C compiler. Looking at the kernel dskio.s routines suggests it's making an upcall to something with the sio instructions which suggests this is the VM/370 version.

The hits keep coming!


On Mon, Oct 28, 2019 at 10:04 PM Warren Toomey <> wrote:
All, the second Unix artifact that I've been waiting to announce has
arrived. This time the LCM+L is announcing it. It's not the booting PDP-7.

So, cast your eyes on

Cheers, Warren

P.S Thanks to Stephen Jones for this as well.