David Laight wrote:
> Dunno, the only non-2s-compliment system I've used did base 10 arithmetic
> with sign overpunch, and had a per process address limit of 1280000 bytes.
> No chance of running anything like unix on that!

"The PDP-11/45 on which our UNIX installation is implemented is a 16-bit
word (8-bit byte) computer with 144K bytes of core memory; UNIX occupies
42K bytes. This system, however, includes a very large number of of device
drivers and enjoys a generous allotment of space for I/O buffers and
system tables; a minimal system capable of running the software mentioned
above can require as little as 50K bytes of core altogether."

D. Ritchie and K. Thompson, 1974.   :D