Convergent Technologies Operating System: Difference between revisions

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{{Short description|Operating system}}

{{Refimprove|article|date=April 2007}}

{{Infobox OS

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The '''Convergent Technologies Operating System''', also known variously as '''CTOS''', '''BTOS''' and '''STARSYS''', wasis a discontinued modular, [[message-passing]], multiprocess-based [[operating system]].

==Overview==

CTOS had many innovative features for its time. System access was controlled with a user password and Volumevolume or disk passwords. If one knew the password, for example, for a volume, one could access any file or directory on that volume (hard disk). Each volume and directory were referenced with delimiters to identify them, and could be followed with a file name, depending on the operation, i.e. {Network Node}[VolumeName]<DirectoryName>FileName.

It was possible to custom-link the operating system to add or delete features.

CTOS supported a transparent [[peer-to-peer network]] carried over serial [[EIA-422|RS-422]] cables (daisy-chain topology) and in later versions carried over [[twisted pair]] ([[star topology]]) with [[RS-422]] adapters using CTOS Cluster Hub-R12 designed by Paul Jackson Ph.D. of SumNet Pty Limited in Australia. Each workgroup (called a "cluster") was connected to a server (called a "master"). The workstations, normally [[diskless workstation|diskless]], were [[Network booting|booted over the cluster network]] from the master, and could optionally be locally booted from attached hard drives.

The [[Inter-process communication]] (IPC) is primarily based on the "request" and "respond" messaging foundation that enhanced the Enterprise Application Integration among services for both internal and external environments. Thus CTOS was well known for the message-based [[Microkernel]] Architecture. Applications are added as services to the main server. Each client consumes the services via its own mailbox called "exchange" and well-published message formats. The communication works on "request codes" that are owned by the service. The operating system maintains the exchanges, message queues, scheduling, control, message passing, etc., while the service manages the messages at its own exchange using "wait", "check", and "respond" macros.

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CTOS ran on [[Intel]] [[x86]] computers, and could run concurrently with [[Windows NT]] on [[Unisys]] PC.

The system [[API]] was presented to both [[high-level languageslanguage]]s and [[assembly language]].

==Programs==

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==Usage==

[[Convergent Technologies]]' first product was the IWS (Integrated Workstation) based on the [[Intel 8086]] processor, which had CTOS as its operating system. This was a modular operating system with built-in [[local area networking]]. CTOS supported multiple processes or threads, and message-based interprocess communication.<ref name="foldoc">{{foldoc|Convergent+Technologies+Operating+System}}</ref>

Companies that licensed CTOS included [[Groupe Bull|Bull]] (STARSYS), and [[Burroughs Corporation|Burroughs]] (BTOS) who later merged with Sperry to become [[Unisys]]. Unisys was the single largest customer and acquired Convergent Technologies in 1988. At its peak, CTOS had over 800,000 users worldwide.

CTOS is no longer marketed to new customers. Former major customers included police forces, banks, airlines, [[Nationwide Insurance]],<ref>{{cite magazine |title=When the mission is critical, leaders plug into BTOS workstations |url=https://books.google.com/books?id=qQUAAAAAMBAJ&pg=PA32#v=twopage |magazine=CIO |date=November 1989}}</ref>, [[U-Haul]],<ref>{{cite news |title=Burroughs contracts with U-Haul |url=https://books.google.com/books?id=mop2UUCt4kIC&pg=PA15 |work=ComputerWorld |date=June 23, 1986 |page=15}}</ref>, the [[U.S. Postal Service]], the [[Drug Enforcement Administration]], the [[U.S. Army]] and the [[United States Coast Guard]]. The Coast Guard used the operating system from approximately 1984 until 2000. In Australia, CTOS/BTOS was used by the [[Trade Practices Commission]], [[Auditor-General of New South Wales|NSW Auditor-General]]'s, CSIRO, Commonwealth Electoral Office, Western Australia Prisons Department and many commercial banks.

Diskless workstations (e.g., ''Bull'') based onSome Convergent's NGENsystems used the [[Intel 80186]] processor, a processor seldom used by standard PCs.

[[Progress Software Corporation]] made a commercial database application for CTOS that was in [[4GL]]. The [[United States Coast Guard]] used these databases for logistics administration for their vessels.

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==References==

{{Reflist}}

* {{cite book

| firstfirst1 = Edna Ilyin

| lastlast1 = Miller

| author2first2 = Jim Crook |author3 = June Loy

| last2 = Crook

| first3 = June

| last3 = Loy

| title = Exploring CTOS

| publisher = [[Prentice Hall]]

| year = 1991

| isbn = 0-13-297342-1 }}

| url = https://archive.org/details/bitsavers_convergentS1991_11080831 }}

==External links==

*[https://web.archive.org/web/20110708212436/http://www.ctosfaq.com/CtosFaqOct1999.htm The CTOS FAQ October 1999]

*[https://web.archive.org/web/20080828190425/http://www.byte.com/art/9412/sec13/art2.htm CTOS Revealed, Byte, December 1994]

*[httphttps://www.angelfire.com/ga/paulmooney/ctos.html Paul Mooney's CTOS Central]

*[https://web.archive.org/web/20111020190645/http://www.ctosfaq.com/CTOSPictures.htm The CTOS FAQ Picture Archive]

*[http://www.softwarepreservation.org/meetings/2006/2006-05-17/CTOS_Intro_2006_05_17.pdf Exhuming CTOS: The Convergent Technologies Project, Nadia Ilyin]

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{{Operating system}}

[[Category:Computer-related1980 introductions in 1980software]]

[[Category:Discontinued operating systems]]

[[Category:Proprietary operating systems]]

[[Category:Unisys operating systems]]

[[Category:X86 operating systems]]