TOPS-20

On Tue, 20 Oct 1998, Sean 'Captain Napalm' Conner wrote: both tcsh and bash will do command completion as well. And some interesting notes from the tcsh manual page: THE T IN TCSH In 1964, DEC produced the PDP-6. The PDP-10 was a later re-implementation. It was re-christened the DECsystem-10 in 1970 or so when DEC brought out the second model, the KI10. TENEX was created at Bolt, Beranek & Newman (a Cambridge, Mass. think tank) in 1972 as an experiment in demand-paged virtual memory operating systems. They built a new pager for the DEC PDP-10 and created the OS to go with it. It was extremely successful in academia. In 1975, DEC brought out a new model of the PDP-10, the KL10; they intended to have only a version of TENEX, which they had licensed from BBN, for the new box. They called their version TOPS-20 (their capitalization is trade- marked). A lot of TOPS-10 users (`The OPerating System for PDP-10') objected; thus DEC found themselves support- ing two incompatible systems on the same hardware--but then there were 6 on the PDP-11! TENEX, and TOPS-20 to version 3, had command completion via a user-code-level subroutine library called ULTCMD. With version 3, DEC moved all that capability and more into the monitor (`kernel' for you Unix types), accessed by the COMND% JSYS (`Jump to SYStem' instruction, the supervisor call mechanism [are my IBM roots also show- ing?]). The creator of tcsh was impressed by this feature and sev- eral others of TENEX and TOPS-20, and created a version of csh which mimicked them.