Company / developer Digital Equipment Corporation
Programmed in MACRO-10, BLISS
OS family DEC OS family
Working state Discontinued
Latest stable release 7.04.[1] / July 1988
Available language(s) ?
Available programming languages(s) APL, ALGOL, BASIC, BLISS, COBOL, Fortran, MACRO-10
Supported platforms PDP-10
Default user interface Command line interface
License Proprietary

The TOPS-10 System (Timesharing / Total OPerating System) was a computer operating system from Digital Equipment Corporation (DEC) for the PDP-10 (or DECsystem-10) mainframe computer launched in 1967. TOPS-10 evolved from the earlier "Monitor" software for the PDP-6 and -10 computers; this was renamed TOPS-10 in 1970.



TOPS-10 supported shared memory and allowed the development of one of the first true multiplayer computer games. The game was called DECWAR[2] and was a text-oriented Star Trek type game. Users at terminals typed in commands and fought each other in real time.

Another groundbreaking application was called FORUM. This application was perhaps the first so-called CB Simulator that allowed users to converse with one another in what is now known as a chat room. This application showed the potential of multiuser communication and led to the development of CompuServe's chat application.

TOPS-10 had a very robust API that used a mechanism called a UUO which is an acronym for Unimplemented User Operation. UUOs implemented operating system calls in a way that made them look like machine instructions. The API was called Monitor Calls and was very much ahead of its time like most of the operating system. System programming on DECsystem-10s was simple and powerful thanks to this extremely flexible operating system API.

TOPS-10 had an interesting scheduler with many run queues, and inserts processes into the queue depending on process priority. The TOPS-10 Operating System also included User file and Device independence.

TOPS-10 was a very fast and flexible operating system that was far ahead of its time.[citation needed]

Release history

The first release of the PDP-6 Monitor software was in 1964. Support for the PDP-10's KA10 processor was added to the Monitor in release 2.18 in 1967. The TOPS-10 name was first used in 1970 for release 5.01. Release 6.01 (May 1974) was the first TOPS-10 to implement Virtual Memory (demand paging) enabling programs larger than physical memory to be run. From release 7.00 onwards symmetrical multiprocessing was available (as opposed to the master - slave concept used before). The final release of TOPS-10 was 7.04 in 1988.[1]

TOPS-10 today

Hobbyists are now entitled to set up and use TOPS-10 under a Hobbyist's License.[3]

The easiest way for the hobbyist to run TOPS-10 is to acquire a suitable emulator[4][5] and an operating system image.[6] TOPS-10 may also be generated from archived original distribution "tapes".[7] [8]

Paul Allen maintains several publicly accessible historic computer systems, including a DECsystem-1090 running TOPS-10.[9]

Implemented programming languages

The TOPS-10 assembler, MACRO-10, was bundled with the TOPS-10 distribution.

The following programming languages were implemented on TOPS-10 as layered products:

  • ALGOL, as ALGOL-10 v10B,[10] a compiler used for general computing
  • APL, as APL-SF V2,[11] an interpreter used for mathematical modelling
  • BASIC, as BASIC-10 v17F,[12] an interpreter used for general computing
  • BLISS, as BLISS-10 and BLISS-36, compilers used for systems programming
  • COBOL, as COBOL-68 and COBOL-74, compilers used for business computing
  • Fortran, as FORTRAN-10 v11, a compiler used for numerical computing

The following programming languages were implemented on TOPS-10 as contributions from DECUS members:

  • FOCAL, as FOCAL-10
  • Forth, a threaded interpreted language
  • IMP72
  • Lisp, an interpreter used for AI programming
  • Pascal, a compiler used for computing education
  • SAM76
  • Simula, a compiler used for modeling
  • SNOBOL, an interpreter used for string processing

Implemented user utilities

The following major user utilities were implemented on TOPS-10:

  • RMS (Records Management Services)
  • IQL (Interactive Query language)

Notable games implemented on TOPS-10


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • TopS BI — TopS Business Integrator Год основания 1991, Москва …   Википедия

  • TOPS-20 — war ein Timesharing Betriebssystem für die 36 Bit Rechnerfamilie der Firma Digital Equipment Corporation, das auf den neueren Zentraleinheiten KL10 und KS10 der PDP 10 eingesetzt werden konnte. Die Kombination PDP 10 und TOPS 20 wurde ab 1976 als …   Deutsch Wikipedia

  • TOPS-10 — (Timesharing / Total OPerating System) операционная система от Digital Equipment Corporation (DEC) для серии мейнфреймов PDP 10 (или DECsystem 10), созданной в 1967. TOPS 10 возникла из раннего программного обеспечения Monitor для компьютеров PDP …   Википедия

  • TOPS-10 — (Timesharing Operating System 10) war ein interaktives Multiuser Betriebssystem der Firma Digital Equipment Corporation (DEC) für die ebenfalls von DEC hergestellten PDP 6 und PDP 10 Rechner. Die erste Version von TOPS 10 war Version 1.4, die… …   Deutsch Wikipedia

  • tops — /tops/, adj. 1. ranked among the highest, as in ability, performance, comprehensiveness, or quality: His work is tops. That car is tops. adv. 2. at a maximum; at most: It ll take an hour, tops. I ll give you $25 for that, tops. n. 3. the tops.… …   Universalium

  • TOPS-20 — est un système d exploitation propriétaire à temps partagé réalisé par Digital Equipment Corporation en janvier 1976[1] pour fonctionner sur ses machines PDP 10 et DEC 20. TOPS 20 est basé sur le système privateur TENEX racheté en 1973 à BBN… …   Wikipédia en Français

  • Tops — may refer to:* Jan Tops (born 1961), a Dutch equestrian * Tops Markets LLC, an American supermarket chainee also* Top (disambiguation) * Topper * Toppers * Topping * TOPS (disambiguation) …   Wikipedia

  • tops — [tɔps US ta:ps] adv spoken informal 1.) at the most ▪ It should take two hours tops. 2.) the best or most popular ▪ The store was voted tops for its outstanding facilities for children …   Dictionary of contemporary English

  • tops — [ taps ] adverb at the most: You could probably get $800 tops for that car …   Usage of the words and phrases in modern English

  • tops — informal a particularly good person or thing. → top tops informal at the most. → top …   English new terms dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.