The UNIX Time-Sharing System†

Abstract

UNIX∗ is a general-purpose, multi-user, interactive operating system for the larger Digital Equipment Corporation PDP-11 and the Interdata 8/32 computers. It offers a number of features seldom found even in larger operating systems, including (i) A hierarchical file system incorporating demountable volumes, (ii) Compatible file, device, and inter-process I/O, (iii) The ability to initiate asynchronous processes, (iv) System command language selectable on a per-user basis, (v) Over 100 subsystems including a dozen languages, (vi) High degree of portability. This paper discusses the nature and implementation of the file system and of the user command interface.