Passing Time

The Evolution of the Unix Time-sharing System

Dennis M. Ritchie:

The processor arrived at the end of the summer, but the PDP-11 was so new a product that no disk was available until December. In the meantime, a rudimentary, core-only version of Unix was written using a cross-assembler on the PDP-7. Most of the time, the machine sat in a corner, enumerating all the closed Knight's tours on a 6×8 chess board—a three-month job.

“Downtime” is only for those with little imagination.