Editing PDP-7 (section)

==Software==
'''DECsys''', the first operating system for DEC's 18-bit computer family (and DEC's first operating system for a computer smaller than its 36-bit timesharing systems), was introduced in 1965. It provides an interactive, single user, program development environment for [[Fortran]] and [[assembly language]] programs.<ref name=DECsys>{{cite web |url=http://simh.trailing-edge.com/docs/decsys.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://simh.trailing-edge.com/docs/decsys.pdf |archive-date=2022-10-09 |url-status=live |title=Technical Notes on DECsys |first=Bob |last=Supnik |date=June 19, 2006}}</ref>

In 1969, [[Ken Thompson]] wrote the first [[Unix|UNIX]] system, then named Unics as a pun on [[Multics]] despite only using two design elements from Multics,<ref>{{cite conference |last=Ritchie |first=Dennis M. |author-link=Dennis Ritchie |year=1977 |title=The Unix Time-sharing System: A retrospective |conference=Tenth Hawaii International Conference on the System Sciences |url=https://www.bell-labs.com/usr/dmr/www/retro.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.bell-labs.com/usr/dmr/www/retro.pdf |archive-date=2022-10-09 |url-status=live |quote=a good case can be made that UNIX is in essence a modern implementation of MIT’s CTSS system}}</ref><ref>{{cite book |last=Seibel |first=Peter |date=2009 |title=Coders at work : reflections on the craft of programming |location=New York |publisher=Apress |page=463 |isbn=9781430219491 |quote=The things that I [Ken Thompson] liked [about Multics] enough to actually take were the hierarchical file system and the shell}}</ref> in assembly language on a PDP-7,<ref>{{cite web |first=Dennis M. |last=Ritchie |url=https://www.bell-labs.com/usr/dmr/www/chist.html |title=The Development of the C Language}}</ref> as the operating system for ''[[Space Travel (video game)|Space Travel]]'', a game which requires graphics to depict the motion of the planets. A PDP-7 was also the development system used during the development of [[MUMPS]] at [[Massachusetts General Hospital|MGH]] in [[Boston]] a few years earlier.