Editing CORAL

{{Short description|Early programming language}}
{{Use dmy dates|date=September 2019}}
{{Use British English|date=September 2019}}
{{Infobox programming language
| name = Coral 66
| logo = <!-- Filename only -->
| logo caption = 
| screenshot = <!-- Filename only -->
| screenshot caption = 
| paradigms = [[Procedural programming|procedural]], [[Imperative programming language|imperative]], [[Structured programming|structured]]
| family = [[ALGOL]]
| designers = [[Philip Woodward]], I. F. Currie, M. Griffiths
| developer = [[Royal Radar Establishment]]
| released = {{Start date and age|1964}}
| latest release version = 
| latest release date = <!-- {{Start date and age|19yy|mm|dd|df=yes}} -->
| typing = [[Static type|Static]], [[Strong and weak typing|strong]]
| scope = [[Scope (computer science)|Lexical]]
| programming language = [[BCPL]]
| discontinued =
| platform = [[Computer Technology Limited|CTL]] [[Computer Technology Limited#Modular One|Modular-1]], [[DEC Alpha]], [[General Electric Company|GEC]], [[Ferranti]], [[Honeywell]], [[HPE Integrity Servers]], Interdata 8/32, [[PDP-11]], [[SPARC]], [[VAX]], [[x86]], [[Intel 8080]], [[Zilog Z80]], [[Motorola 68000]]
| operating system = [[OpenVMS]],<ref>{{cite web|url=https://assets1.dxc.technology/manufacturing/downloads/MD_6841a-18_Coral_Offer_Overview_v4.pdf |archive-url=https://web.archive.org/web/20210123102547/https://assets1.dxc.technology/manufacturing/downloads/MD_6841a-18_Coral_Offer_Overview_v4.pdf |archive-date=2021-01-23 |url-status=live|title=Gain the advantage with CORAL, CORAL+ and Context|publisher=[[DXC Technology]]|date=September 2017|access-date=2021-12-29}}</ref> [[Berkeley Software Distribution|BSD]] [[Unix]], [[Linux]], [[Solaris (operating system)|Solaris]]
| license = 
| file ext = 
| file format = <!-- or: | file formats = -->
| website = <!-- {{URL|www.example.com}} -->
| implementations = 
| dialects = 
| influenced by = [[ALGOL]], [[JOVIAL]], [[Fortran]]
| influenced = 
}}

'''CORAL''', short for '''Computer On-line Real-time Applications Language''' is a [[programming language]] originally developed in 1964 at the [[Royal Radar Establishment]] (RRE), [[Malvern, Worcestershire]], in the United Kingdom.<ref name="Ferranti_1968"/> The R was originally for "radar", not "real-time".<ref>{{cite book |first=Jack |last=Gough |title=Watching the skies: a history of ground radar for the air defence of the United Kingdom by the Royal Air Force from 1946 to 1975 |publisher=HMSO |isbn=978-0-11-772723-6 |date=1993 |url=https://books.google.com/books?id=VHcfAQAAIAAJ |page=264}}</ref> It was influenced primarily by [[JOVIAL]], and thus [[ALGOL]], but is not a [[subset]] of either.

The most widely-known version, '''CORAL 66''', was subsequently developed by I. F. Currie and M. Griffiths under the auspices of the ''Inter-Establishment Committee for Computer Applications'' (IECCA). Its official definition, edited by [[Philip Woodward|Woodward]], Wetherall, and Gorman, was first published in 1970.<ref>{{cite book |last=Woodward |first=Philip M. |author-link=Philip Woodward |date=1970 |title=Official Definition of CORAL 66 |url=https://archive.org/details/official-definition-of-coral-66 |publisher=[[Office of Public Sector Information|Her Majesty's Stationery Office]] (HMSO) |pages=vii+58 |isbn=0114702217 |via=[[Internet Archive]]}}</ref>

In 1971, CORAL was selected by the [[Ministry of Defence (United Kingdom)|Ministry of Defence]] as the language for future military applications and to support this, a standardization program was introduced to ensure CORAL compilers met the specifications. This process was later adopted by the [[US Department of Defense]] while defining [[Ada programming language|Ada]].

== Overview ==

Coral 66 is a [[general-purpose programming language]] based on [[ALGOL 60]], with some features from Coral 64, [[JOVIAL]], and [[Fortran]]. It includes structured record types (as in [[Pascal (programming language)|Pascal]]) and supports the packing of data into limited storage (also as in Pascal). Like [[Edinburgh IMP]] it allows [[Inline assembler|inline]] (embedded) [[assembly language]], and also offers good [[Runtime (program lifecycle phase)|runtime]] checking and diagnostics. It is designed for [[real-time computing]] and [[embedded system]] applications, and for use on computers with limited processing power, including those limited to [[fixed-point arithmetic]] and those without support for dynamic storage allocation.

The language was an inter-service standard for British military programming,<ref>{{Cite web |title=Coral 66 - Language Reference Manual - Manual - Computing History |url=https://www.computinghistory.org.uk/det/32364/Coral-66-Language-Reference-Manual/ |archive-url=https://web.archive.org/web/20230731185340/https://www.computinghistory.org.uk/det/32364/Coral-66-Language-Reference-Manual/ |archive-date=2023-07-31 |access-date=2023-07-31 |website=www.computinghistory.org.uk}}</ref> and was also widely adopted for civil purposes in the British control and automation industry. It was used to write software for both the [[Ferranti]]<ref name=RSRE799->{{cite report |url=https://apps.dtic.mil/sti/citations/ADA084068 |archive-url=https://web.archive.org/web/20210317073041/http://www.dtic.mil/docs/citations/ADA084068 |url-status=live |archive-date=17 March 2021 |title=The Coral 66 Compiler for Ferranti ARGUS 500 Computer |last=Gorman |first=B |publisher=Royal Signals and Radar Establishment |date=June 1978 |id=Technical Note 799 |access-date=17 January 2018}}</ref> and [[GEC Computers|General Electric Company]] (GEC) computers from 1971 onwards. Implementations also exist for the Interdata 8/32, [[PDP-11]], [[VAX]] and [[DEC Alpha|Alpha]] platforms and [[HPE Integrity Servers]]; for the [[Honeywell]], and for the [[Computer Technology Limited]] (CTL, later ITL) [[Computer Technology Limited#Modular One|Modular-1]];<ref name=nsci-19721130/> and for [[SPARC]] running [[Solaris (operating system)|Solaris]], and [[Intel]] running [[Linux]].

Queen [[Elizabeth II]] sent the first email from a [[head of state]] from the [[Royal Signals and Radar Establishment]] over the [[ARPANET]] on March 26, 1976. The message read "This message to all ARPANET users announces the availability on ARPANET of the Coral 66 compiler provided by the [[GEC 4000 series|GEC 4080]] computer at the Royal Signals and Radar Establishment, Malvern, England, ... Coral 66 is the standard real-time high level language adopted by the [[Ministry of Defence (United Kingdom)|Ministry of Defence]]."<ref>{{Cite news |url=https://www.wired.com/2012/12/queen-and-the-internet/ |title=How the Queen of England Beat Everyone to the Internet |last=Metz |first=Cade |date=2012-12-25 |work=Wired |access-date=2020-01-09 |issn=1059-1028}}</ref><ref>{{Cite news |last=Left |first=Sarah |url=https://www.theguardian.com/technology/2002/mar/13/internetnews |title=Email timeline |date=2002-03-13 |work=The Guardian |access-date=2020-01-09 |language=en-GB |issn=0261-3077}}</ref>

As Coral was aimed at a variety of real-time work, rather than general office data processing, there was no standardised equivalent to a [[stdio]] [[Library (computing)|library]]. IECCA recommended a primitive [[input/output]] (I/O) package to accompany any compiler (in a document titled ''Input/Output of Character data in Coral 66 Utility Programs''). Most implementers avoided this by producing Coral interfaces to extant Fortran and, later, [[C (programming language)|C]] libraries.

CORAL's most significant contribution to computing may have been enforcing [[quality control]] in commercial [[compiler]]s.<ref name="nsci-19721130">{{cite news |url=https://books.google.com/books?id=dkUzDol9AcQC |title=Lucid language may help European computers |magazine=New Scientist |page=513 |date=30 November 1972 |access-date=8 April 2019}}</ref> To have a CORAL compiler approved by IECCA, and thus allowing a compiler to be marketed as a CORAL 66 compiler, the candidate compiler had to compile and execute a standard suite of 25 test programs and 6 benchmark programs. The process was part of the [[British Standard]] (BS) 5905 approval process. This methodology was observed and adapted later by the [[United States Department of Defense]] for the certification of [[Ada (programming language)|Ada]] compilers.

[[Source code]] for a Coral 66 compiler (written in [[BCPL]]) has been recovered and the ''Official Definition of Coral 66'' document by [[Office of Public Sector Information|Her Majesty's Stationery Office]] (HMSO) has been scanned; the Ministry of Defence patent office has issued a licence to the Edinburgh Computer History project to allow them to put both the code and the language reference online for non-commercial use.

== Variants ==
A variant of Coral 66 named PO-CORAL was developed during the late 1970s to early 1980s by the British [[General Post Office]] (GPO), together with [[General Electric Company|GEC]], STC and [[Plessey]], for use on the [[System X (telephony)|System X]] digital telephone exchange control computers. This was later renamed BT-CORAL when [[British Telecom]] was spun off from the Post Office. Unique features of this language were the focus on real-time execution, message processing, limits on statement execution between waiting for input, and a prohibition on recursion to remove the need for a [[Stack (abstract data type)|stack]].{{Citation needed|date=December 2020}}

== References ==
{{Reflist|refs=
<ref name="Ferranti_1968">{{cite book |title=FM1600B Microcircuit Computer Ferranti Digital Systems |date=October 1968 |orig-year=September 1968 |publisher=[[Ferranti Limited]], Digital Systems Department |location=Bracknell, Berkshire, UK |id=List DSD 68/6 |url=https://www.sba.unipi.it/sites/default/files/2015_05_29_08_44_13.pdf |access-date=2020-05-19 |url-status=live |archive-url=https://web.archive.org/web/20200519075443/https://www.sba.unipi.it/sites/default/files/2015_05_29_08_44_13.pdf |archive-date=2020-05-19}}</ref>
}}

== External links ==
* [http://history.dcs.ed.ac.uk/archive/os/deimos/ercm09/emas-2900/coral2.txt CORAL 66 test program] extracted from the [http://history.dcs.ed.ac.uk/archive/os/emas/users/ercm09/emas-2900/coral.txt Test Responder report]
* [https://web.archive.org/web/20041102162930/http://yfroom.8800.org/apps/1750/benchmarks/coral66/ CORAL 66 benchmarks]
* [https://web.archive.org/web/20070927041856/http://standards.mackido.com/bs/bs-standards24_view_4284.html BS5905] CORAL 66 Standard
* [https://web.archive.org/web/20100216045637/http://www.dstan.mod.uk/data/05/047/00000200.pdf DEF STAN 05-47]
* [http://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/rsx/decus/rsx82b/312022/ PDP-11 CORAL/ASM interfacing library]
* ECCE [http://history.dcs.ed.ac.uk/archive/os/emas/users/ercm09/emas-2900/coraltrans.txt editor script to translate CORAL 66] into [[Edinburgh IMP]]

{{ALGOL programming}}

[[Category:History of computing in the United Kingdom]]
[[Category:Procedural programming languages]]
[[Category:Programming languages created in 1964]]