rsts

RSTS, short for Resource Sharing Time Sharing System, is a family of early multi-user time-sharing operating systems developed for Digital Equipment Corporation’s PDP-11 line in the 1970s. It was designed to allow several users to interact with a single computer system through terminals, enabling simultaneous programming, data processing, and batch jobs under a single time-sharing environment.

A common variant is RSTS/E, an extended version that added features for networked resource sharing and system administration. RSTS/E supported multiple PDP-11 systems sharing disks and peripherals over a network, broadening the scope of collaboration and resource use beyond a single machine. The operating system typically provided a basic file system, user accounts and access controls, program development tools, and simple interprocess communication, with scheduling based on time slicing to serve multiple terminals efficiently.

Hardware and usage contexts for RSTS centered on PDP-11 hardware in academic, research, and small-business environments. Terminals connected to a central server allowed interactive work, debugging, and teaching environments where many users could work concurrently.

Legacy and significance: RSTS represents an important step in the evolution of multi-user and networked computing on minicomputers, contributing to later DEC platforms and influencing concepts in resource sharing and centralized administration. As DEC’s ecosystem shifted toward RSX-11 successors and, later, VMS on VAX systems, installations of RSTS declined, though historical documentation and preserved systems remain of interest to enthusiasts and researchers.

Note: RSTS is distinct from other DEC environments such as RSX-11 and RT-11, and the acronym may appear in other contexts, but the historical RSTS primarily refers to Resource Sharing Time Sharing System and its extensions.