[TUHS] Bootstrapping UNIX - how was it done

[Warner Losh via TUHS]

On Mon, Mar 23, 2026 at 12:48 PM Dan Cross via TUHS <tuhs at tuhs.org> wrote:

> On Mon, Mar 23, 2026 at 1:54 PM segaloco via TUHS <tuhs at tuhs.org> wrote:
> > On Monday, March 23rd, 2026 at 02:05, Adam Koszek via TUHS <
> tuhs at tuhs.org> wrote:
> > > What editors were used for early B, B+, C and early kernel?
> >
> > My understanding is that prior to UNIX being self hosting, Ken was
> > editing things in QED under GECOS on the 645 BTL had gotten for Multics
> > development, carrying over the PPT output to then load up on the PDP-7.
>
> I believe it was a GE-635 that was used for bootstrapping Unix onto the
> PDP-7:
>
> https://www.read.seas.harvard.edu/~kohler/class/aosref/ritchie84evolution.pdf
>
> Despite the similarity in name, the 635 and 645 were very different
> machines.
>

In my history of Unix talks, I spoke of Ken creating paper tapes that were
loaded by the PDP-7 on the GE to get going. First to get SpaceWar going,
then to get the 'paper filesystem' going, which turned into the unix
kernel...

Warner