Editing Computer programming (section)

==History==
[[File:Ada lovelace.jpg|thumb|[[Ada Lovelace]], whose notes were added to the end of [[Luigi Menabrea]]'s paper included the first [[algorithm]] designed for processing by [[Charles Babbage]]'s [[Analytical Engine]]. She is often recognized as history's first computer programmer.]]
{{See also|Computer program#History|Programmer#History|History of programming languages}}

[[Program (machine)|Programmable devices]] have existed for centuries. As early as the 9th century, a programmable [[music sequencer]] was invented by the Persian [[Banu Musa]] brothers, who described an automated mechanical [[flute]] player in the ''[[Book of Ingenious Devices]]''.<ref name=Koetsier>{{cite journal |last1=Koetsier |first1=Teun  |year=2001 |title=On the prehistory of programmable machines: musical automata, looms, calculators |journal=Mechanism and Machine Theory |volume=36 |issue=5 |pages=589–603 |publisher=Elsevier |doi=10.1016/S0094-114X(01)00005-2 }}</ref><ref>{{cite journal |last1=Kapur |first1=Ajay |last2=Carnegie |first2=Dale |last3=Murphy |first3=Jim |last4=Long |first4=Jason |title=Loudspeakers Optional: A history of non-loudspeaker-based electroacoustic music |journal=[[Organised Sound]] |date=2017 |volume=22 |issue=2 |pages=195–205 |doi=10.1017/S1355771817000103 |publisher=[[Cambridge University Press]] |issn=1355-7718|doi-access=free }}</ref> In 1206, the Arab engineer [[Al-Jazari]] invented a programmable [[drum machine]] where a musical mechanical [[automaton]] could be made to play different rhythms and drum patterns, via pegs and [[Cam (mechanism)|cam]]s.<ref>{{Cite journal|title=The Museum of Music: A History of Mechanical Instruments|first=Charles B.|last=Fowler|journal=Music Educators Journal|volume=54|issue=2|date=October 1967|pages=45–49|doi=10.2307/3391092|jstor=3391092|s2cid=190524140}}</ref><ref name=Sharkey>[[Noel Sharkey]] (2007), [https://web.archive.org/web/20070629182810/http://www.shef.ac.uk/marcoms/eview/articles58/robot.html A 13th Century Programmable Robot], [[University of Sheffield]]</ref> In 1801, the [[Jacquard loom]] could produce entirely different weaves by changing the "program" – a series of [[Card stock|pasteboard]] cards with holes punched in them.

[[Code-breaking]] algorithms have also existed for centuries. In the 9th century, the [[Mathematics in medieval Islam|Arab mathematician]] [[Al-Kindi]] described a [[cryptographic]] algorithm for deciphering encrypted code, in ''A Manuscript on Deciphering Cryptographic Messages''. He gave the first description of [[cryptanalysis]] by [[frequency analysis]], the earliest code-breaking algorithm.<ref>{{cite book |last1=Dooley |first1=John F. |title=A Brief History of Cryptology and Cryptographic Algorithms |date=2013 |publisher=Springer Science & Business Media |isbn=9783319016283 |pages=12–3}}</ref>

The first [[computer program]] is generally dated to 1843 when mathematician [[Ada Lovelace]] published an [[algorithm]] to calculate a sequence of [[Bernoulli numbers]], intended to be carried out by [[Charles Babbage]]'s [[Analytical Engine]].<ref name="IEEE">{{Cite journal | last1 = Fuegi | first1 = J. | last2 = Francis | first2 = J. | title = Lovelace & Babbage and the Creation of the 1843 'notes' | journal = IEEE Annals of the History of Computing | volume = 25 | issue = 4 | pages = 16 | year = 2003 | doi = 10.1109/MAHC.2003.1253887}}</ref> The algorithm, which was conveyed through notes on a translation of Luigi Federico Menabrea's paper on the analytical engine was mainly conceived by Lovelace as can be discerned through her correspondence with Babbage. However, Charles Babbage himself had written a program for the AE in 1837.<ref name="IEEE2021">{{Cite journal | last1 = Rojas | first1 = R. | title = The Computer Programs of Charles Babbage | journal = IEEE Annals of the History of Computing | volume = 43 | issue = 1 | pages = 6–18 | year = 2021 | doi = 10.1109/MAHC.2020.3045717}}</ref><ref name="IEEE2024">{{Cite journal | last1 = Rojas | first1 = R. | title = The First Computer Program | journal = Communications of the ACM | volume = 67 | issue = 6 | pages = 78–81 | year = 2024 | doi = 10.1145/3624731| doi-access = free | url = https://refubium.fu-berlin.de/bitstream/fub188/44090/1/3624731.pdf }}</ref> Lovelace was also the first to see a broader application for the analytical engine beyond mathematical calculations. 

[[File:PunchCardDecks.agr.jpg|thumb|Data and instructions were once stored on external [[punched card]]s, which were kept in order and arranged in program decks.]]
In the 1880s, [[Herman Hollerith]] invented the concept of storing ''data'' in machine-readable form.<ref>{{cite web|url=http://www.columbia.edu/acis/history/hollerith.html|title=Columbia University Computing History – Herman Hollerith|last=da Cruz|first=Frank|date=2020-03-10|website=Columbia University|publisher=Columbia.edu|url-status=live|archive-url=https://web.archive.org/web/20200429210742/http://www.columbia.edu/cu/computinghistory/hollerith.html|archive-date=2020-04-29|access-date=2010-04-25}}</ref> Later a [[plugboard|control panel]] (plug board) added to his 1906 Type I Tabulator allowed it to be programmed for different jobs, and by the late 1940s, [[unit record equipment]] such as the [[IBM 602]] and [[IBM 604]], were programmed by control panels in a similar way, as were the first [[electronic computer]]s. However, with the concept of the [[stored-program computer]] introduced in 1949, both programs and data were stored and manipulated in the same way in [[computer memory]].<ref>{{cite web |title=Memory & Storage {{!}} Timeline of Computer History {{!}} Computer History Museum |url=https://www.computerhistory.org/timeline/memory-storage/ |website=www.computerhistory.org |access-date=3 June 2021 |archive-date=May 27, 2021 |archive-url=https://web.archive.org/web/20210527071533/https://www.computerhistory.org/timeline/memory-storage/ |url-status=live }}</ref>

===Machine language===
[[Machine code]] was the language of early programs, written in the [[instruction set architecture|instruction set]] of the particular machine, often in [[binary numeral system|binary]] notation. [[Assembly language]]s were soon developed that let the programmer specify instructions in a text format (e.g., ADD X, TOTAL), with abbreviations for each operation code and meaningful names for specifying addresses. However, because an assembly language is little more than a different notation for a machine language,  two machines with [[Comparison of instruction set architectures|different instruction sets]] also have different assembly languages.

[[File:IBM402plugboard.Shrigley.wireside.jpg|thumb|Wired [[plugboard|control panel]] for an [[IBM 402 Accounting Machine]]. Wires connect pulse streams from the card reader to counters and other internal logic and ultimately to the printer.]]

===Compiler languages===
{{See also|Compiler}}
[[High-level language]]s made the process of developing a program simpler and more understandable, and less bound to the underlying [[Computer hardware|hardware]]. 
The first compiler related tool, the [[A-0 System]], was developed in 1952<ref>{{cite book |last1=Ridgway|first1=Richard|title=Proceedings of the 1952 ACM national meeting (Toronto) on - ACM '52 |chapter=Compiling routines |date=1952|pages=1–5|doi=10.1145/800259.808980|isbn=9781450379250|s2cid=14878552|doi-access=free}}</ref> by [[Grace Hopper]], who also coined the term 'compiler'.<ref name="wikles1968">[[Maurice V. Wilkes]]. 1968. Computers Then and Now. Journal of the Association for Computing Machinery, 15(1):1–7, January. p. 3 (a comment in brackets added by editor), "(I do not think that the term compiler was then [1953] in general use, although it had in fact been introduced by Grace Hopper.)"</ref><ref name="computerhistory.org">[http://www.computerhistory.org/events/lectures/cobol_06121997/index.shtml] The World's First COBOL Compilers   {{webarchive|url=https://web.archive.org/web/20111013021915/http://www.computerhistory.org/events/lectures/cobol_06121997/index.shtml|date=13 October 2011}}</ref> [[FORTRAN]], the first widely used high-level language to have a functional implementation, came out in 1957,<ref name = bergstein>{{cite web|url=https://www.nbcnews.com/id/wbna17704662|title=Fortran creator John Backus dies |last=Bergstein|first=Brian|date=2007-03-20|website=NBC News|url-status= live|archive-url=https://web.archive.org/web/20200429211030/http://www.nbcnews.com/id/17704662|archive-date=2020-04-29 |access-date=2010-04-25}}</ref> and many other languages were soon developed—in particular, [[COBOL]] aimed at commercial data processing, and [[Lisp (programming language)|Lisp]] for computer research.

These compiled languages allow the programmer to write programs in terms that are syntactically richer, and more capable of [[abstraction (computer science)|abstracting]] the code, making it easy to target varying machine instruction sets via compilation declarations and [[Heuristic (computer science)|heuristics]]. Compilers harnessed the power of computers to make programming easier<ref name = bergstein/> by allowing programmers to specify calculations by entering a formula using [[infix notation]].

===Source code entry===
{{See also|Computer programming in the punched card era}}
Programs were mostly entered using punched cards or [[paper tape]]. By the late 1960s, [[data storage device]]s and [[computer terminal]]s became inexpensive enough that programs could be created by typing directly into the computers. [[Text editor]]s were also developed that allowed changes and corrections to be made much more easily than with [[Punched card sorter|punched cards]].