Related:

• OS /O-S/ 1. [Operating System] n. An abbreviation heavily used in email, occasionally in speech.
  2. n. obs. On ITS, an output spy. See "OS and JEDGAR" in Appendix A....
• exec: /eg-zek'/ vt., n. 1. [UNIX: from `execute'] Synonym for {chain}, derives from the `exec(2)' call.
  2. [from `executive'] obs. The command interpreter for an {OS} (see {shell})...
• TOPS-10:: /tops-ten/ n. DEC's proprietary OS for the fabled {PDP-10} machines, long a favorite of hackers but now effectively extinct.
  A fountain of hacker folklore; see {Appendix A}....
• ystem: n. 1. The supervisor program or OS on a computer.
  2. The entire computer system, including input/output devices, the supervisor program or OS, and possibly other software....
• ap: 1. n. A program interrupt, usually an interrupt caused by some exceptional situation in the user program.
  In most cases, the OS performs some action, then returns control to the program....
• ITS /I-T-S/ n. 1. Incompatible Time-sharing System, an influential though highly idiosyncratic operating system written for PDP-6s and PDP-10s at MIT and long used at the MIT AI Lab.
  Much AI-hacker jargon derives from ITS folklore, and to have been `an ITS hacker' qualifies one instantly as an old-timer of the most venerable sort....
• TOPS-10 /tops-ten/ n. DEC's proprietary OS for the fabled PDP-10 machines, long a favorite of hackers but now effectively extinct.
  A fountain of hacker folklore; see Appendix A....
• oot: [UNIX] n. 1. The {superuser} account (with user name `root') that ignores permission bits, user number 0 on a UNIX system.
  The term {avatar} is also used. 2. The top node of the system directory structure (home directory of the root user)....
• X: /X/ n. 1. Used in various speech and writing contexts (also in lowercase) in roughly its algebraic sense of `unknown within a set defined by context' (compare {N}).
  Thus, the abbreviation 680x0 stands for 68000, 68010, 68020, 68030, or 68040, and 80x86 stands for 80186, 80286 80386 or 80486 (note that a UNIX hacker might write these as 680[0-4]0 and 80[1-4]86 or 680?...