TOPS-20
Sign in to saveAlso known as Twenex
The TOPS-20 operating system by Digital Equipment Corporation (DEC) is a proprietary OS used on some of DEC's 36-bit mainframe computers. The Hardware Reference Manual was described as for "DECsystem-10/DECSYSTEM-20 Processor" (meaning the DEC PDP-10 and the DECSYSTEM-20).
Key facts
- OS.language
- English
- OS.name
- TOPS-20
- OS.screenshot
- TOPS-20.png
- OS.caption
- Screenshot of login prompt of a TOPS-20 system
- OS.developer
- Digital Equipment Corporation
- OS.supported_platforms
- PDP-10
- OS.latest_release_version
- 7.1
- OS.marketing_target
- Mainframe computers
- OS.programmed_in
- Assembly language
- OS.working_state
- Discontinued
- OS.ui
- Command-line interface
- OS.license
- Proprietary
- OS.preceded by
- TENEX
- OS.family
- TENEX
via Wikipedia infobox
~6 min read
Encyclopedic overview
14 sectionsContents
- TENEX
- PA1050
- TOPS-20 capabilities
- Command processor
- Available programming languages
- Commands
- JSYS features
- PCL (Programmable Command Language)
- PCL language features
- TOPS-20 today
- See also
- References
- Further reading
- External links
The TOPS-20 operating system by Digital Equipment Corporation (DEC) is a proprietary OS used on some of DEC's 36-bit mainframe computers. The Hardware Reference Manual was described as for "DECsystem-10/DECSYSTEM-20 Processor" (meaning the DEC PDP-10 and the DECSYSTEM-20).
TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman (BBN) and shipped as a product by DEC starting in 1976. TOPS-20 is almost entirely unrelated to the similarly named TOPS-10, but it was shipped with the PA1050 TOPS-10 Monitor Calls emulation facility which allowed most, but not all, TOPS-10 executables to run unchanged. As a matter of policy, DEC did not update PA1050 to support later TOPS-10 additions except where required by DEC software.
Excerpted from Wikipedia’s “TOPS-20” article, available under the CC BY-SA 4.0 licence.