View source for TRIPOS

{{Use dmy dates|date=April 2022}}
{{more footnotes needed|date=May 2012}}
{{Infobox OS
| name                   = TRIPOS
| logo                   = 
| screenshot             = 
| caption                = 
| developer              = [[University of Cambridge]], [[University of Bath]], [[MetaComCo]], [[Open G I]]
| source_model           = 
| kernel_type            = 
| supported_platforms    = [[PDP-11]], [[Computer Automation|Computer Automation LSI4]], [[Data General Nova]], [[Motorola 68000]], [[Intel 8086]], [[Cintcode BCPL]] ([[virtual machine|VM]])
| ui                     = 
| family                 = 
| released               = {{Start date and age|1978}}
| latest_release_version = 
| latest_release_date    = 
| latest_test_version    = 
| latest_test_date       = 
| marketing_target       = 
| programmed_in          = [[BCPL]], [[Assembly language]]
| prog_language          = 
| language               = 
| updatemodel            = 
| package_manager        = 
| working_state          = Discontinued
| license                = 
| website                = 
}}
'''TRIPOS''' ('''Trivial Portable Operating System''') is a [[computer]] [[operating system]]. Development started in 1976 at the [[University of Cambridge Computer Laboratory|Computer Laboratory]] of [[University of Cambridge|Cambridge University]] and it was headed by Dr. [[Martin Richards (computer scientist)|Martin Richards]]. The first version appeared in January 1978 and it originally ran on a [[PDP-11]]{{citation needed|date=November 2015}}. Later it was ported to the [[Computer Automation|Computer Automation LSI4]] and the [[Data General Nova]]. Work on a [[Motorola 68000]] version started in 1981 at the [[University of Bath]]. [[MetaComCo]] acquired the rights to the 68000 version and continued development until TRIPOS was chosen by [[Commodore International|Commodore]] in March 1985 to form part of an operating system for their new [[Amiga]] computer; it was also used at Cambridge as part of the [[Cambridge Distributed Computing System]].

Students in the [[Department of Computer Science and Technology, University of Cambridge|Computer Science department at Cambridge]] affectionately refer to TRIPOS as the ''Terribly Reliable, Incredibly Portable Operating System''. The name TRIPOS also refers to the [[Tripos|Tripos system of undergraduate courses and examinations]], which is unique to Cambridge University.

== Influences on the Amiga computer ==
In July 1985, the [[Amiga]] was introduced, incorporating TRIPOS in the [[AmigaDOS]] module of [[AmigaOS]]. AmigaDOS included a [[command-line interface]] and the [[Amiga Old File System|Amiga File System]]. The entire AmigaDOS module was originally written in [[BCPL]] (an ancestor of the [[C (programming language)|C programming language]]), the same language used to write TRIPOS. AmigaDOS would later be rewritten in C from AmigaOS 2.x onwards, retaining backwards compatibility with 1.x up until [[AmigaOS 4]] (completely rewritten in C) when AmigaDOS abandoned its BCPL legacy.

== Features ==
TRIPOS provided features such as [[pre-emptive multi-tasking]] (using strict-priority scheduling), a [[hierarchical file system]] and multiple [[command line interpreter]]s.

The most important TRIPOS concepts have been the non-memory-management approach (meaning no checks are performed to stop programs from using unallocated memory) and message passing by means of passing pointers instead of copying message contents. Those two concepts together allowed for sending and receiving over 1250 packets per second on a 10&nbsp;MHz [[Motorola 68010]] CPU.

Most of TRIPOS was implemented in [[BCPL]]. The [[kernel (operating system)|kernel]] and [[device driver]]s were implemented in [[assembly language]].

One notable feature of TRIPOS/BCPL was its cultural use of shared libraries, untypical at the time, resulting in small and therefore fast loading utilities.  For example, many of the standard system utilities were well below 0.5 Kbytes in size, compared to a typical minimum of about 20 Kbytes for functionally equivalent code on a modern Unix or Linux.{{OR|date=September 2025}}

TRIPOS was ported to a number of machines, including the [[Data General Nova|Data General Nova 2]], the Computer Automation LSI4, [[Motorola 68000]] and [[Intel 8086]]- based hardware. It was offered as the standard operating system on the Microbox III, a computer based on the Motorola 68010 produced by Micro Concepts, alongside alternatives such as [[CP/M]] and [[OS-9]].<ref name="practicalcomputing198607_microbox">{{ cite magazine | url=https://archive.org/details/practical-computing/PracticalComputing-1986-07/page/54/mode/2up | title=Microbox III Graphics for the Specialist | magazine=Practical Computing | last1=Moody | first1=Glyn | date=July 1986 | access-date=16 July 2024 | pages=54–55 }}</ref> It included support for the [[Cambridge Ring (computer network)|Cambridge Ring]] [[local area network]]. More recently,{{when|date=May 2015}} Martin Richards produced a port of TRIPOS to run under [[Linux]], using [[Cintcode BCPL]] virtual machine.

{{Asof|2020|2}}, TRIPOS is still actively maintained by [[Open G I|Open G I Ltd.]] (formerly [[Misys Financial Systems]]) in [[Worcestershire]], [[UK]]. Many British [[insurance broker]]s have a Linux/Intel based{{clarify|date=May 2021}} TRIPOS system serving networked workstations over a [[Internet protocol suite|TCP/IP]] connection—the systems are used to run Open G I's [[BROOMS Application suite]].{{Citation needed|date=May 2015}} Open G I have added a number of features to support the modern office such as the ability to integrate into many mainstream applications and services such as SQL server, Citrix XENAPP, terminal servers, etc.{{cn|date=January 2025}}

=== Commands ===
The following list of [[command (computing)|commands]] is supported by the TRIPOS CLI.<ref>{{cite web |url=https://archive.org/details/1986-metacomco-intro-to-tripos|title=Introduction to Tripos |author=<!--Not stated--> |date=May 1986 |publisher=METACOMCO plc. |access-date=November 29, 2022}}</ref>

{{div col|colwidth=9em}}
* ALINK
* ASSEM
* ASSIGN
* BREAK
* C
* [[cd (command)|CD]]
* CONSOLE
* [[copy (command)|COPY]]
* [[date (command)|DATE]]
* [[del (command)|DELETE]]
* [[dir (command)|DIR]]
* [[diskcopy|DISKCOPY]]
* DISKDOCTOR
* [[echo (command)|ECHO]]
* ED
* EDIT
* ENDCLI
* FAILAT
* FAULT
* FILENOTE
* [[format (command)|FORMAT]]
* IF
* INFO
* INSTALL
* JOIN
* LAB
* LIST
* [[MAKEDIR]]
* [[mount (Unix)|MOUNT]]
* NEWCLI
* PATH
* PROMPT
* PROTECT
* [[quit (command)|QUIT]]
* RELABEL
* [[ren (command)|RENAME]]
* RUN
* SEARCH
* SKIP
* [[sort (Unix)|SORT]]
* STACK
* STATUS
* [[TYPE (DOS command)|TYPE]]
* [[Visual Display Unit|VDU]]
* WAIT
* WHY
{{div col end}}

== Cintpos ==
'''Cintpos''' is an experimental interpretive version of TRIPOS which runs on the [[Cintcode BCPL]] [[virtual machine]], also developed by Martin Richards.

== References ==
{{Reflist}}
{{refbegin}}
* [http://www.pagetable.com/?p=193 Reference manuals]
* [http://www.cl.cam.ac.uk/~mr10/Cintpos.html Martin Richards' Cintpos page]
* [http://www.cl.cam.ac.uk/UoCCL/misc/EDSAC99/history.html A brief informal history of the Computer Laboratory]
* [https://web.archive.org/web/20190420095854/http://www.thule.no/haynie/caos.html In the beginning was CAOS]
{{refend}}

== Further reading ==
* {{cite journal |first1=M. |last1=Richards |first2=A. |last2=Aylward |first3=P. |last3=Bond |first4=R. |last4=Evans |first5= B. J. |last5=Knight |title=TRIPOS—a portable operating system for mini-computers |journal=Software: Practice and Experience |year=1979 |volume=9 |issue=7 |pages=513–526 |doi=10.1002/spe.4380090702 |s2cid=2847052}}
* {{cite book|author=M. Richards|title=The TRIPOS Operating System|year=1988}}

== External links ==
{{Portal|Amiga}}
* [https://web.archive.org/web/20131016145634/http://www.amigahistory.co.uk/tripos.html Amiga history guide: TripOS/68k]
* [http://koo.corpus.cam.ac.uk/projects/stallonecomputer/index.html CBG Stallone Computer]

{{AmigaOS}}

[[Category:Amiga]]
[[Category:Computer-related introductions in 1978]]
[[Category:Discontinued operating systems]]
[[Category:History of computing in the United Kingdom]]
[[Category:University of Cambridge Computer Laboratory]]
[[Category:X86 operating systems]]