TOPS-20

On Tue, 20 Oct 1998, Cameron Kaiser wrote: (regarding tcsh and filename / command completion) Tcsh will do command completion for names of executables that are in the current path. Additionally, typing the ambiguous beginning of a command name followed by ^D will return a list of possible commands in the path that start with the characters that you have entered. Of course, it's important (at least in the context of this thread) to remember where the "t" in tcsh comes from. From Richard M. Alderson III's comments in the tcsh man 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 trademarked). A lot of TOPS-10 users (`The OPerating System for PDP-10') objected; thus DEC found themselves supporting 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 showing?]). The creator of tcsh was impressed by this feature and several others of TENEX and TOPS-20, and created a version of csh which mimicked them. -- Scott Ware NUMS-MPBC Macromolecular Crystallography Resource 303 East Chicago Avenue, Ward 8-264, Chicago, IL 60611 (312)503-0813 PGP Public Key: http://xtal.pharm.nwu.edu/~ware/public.txt