Programmable devices have existed at least as far back as 1206 AD, when the automata of Al-Jazari were programmable, via pegs and cams, to play various rhythms and drum patterns; and the 1801 Jacquard loom could produce entirely different weaves by changing the "program" - a series of pasteboard cards with holes punched in them.
However, 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. Women would continue to dominate the field of computer programming until the mid 1960s.
Data and instructions were once stored on external punched cards
, 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. Later a control panel (plugboard) 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 computers. However, with the concept of the stored-program computers introduced in 1949, both programs and data were stored and manipulated in the same way in computer memory.
Machine code was the language of early programs, written in the instruction set of the particular machine, often in binary notation. Assembly languages were soon developed that let the programmer specify instruction 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, any two machines with different instruction sets also have different assembly languages. Kathleen Booth created one of the first Assembly languages in 1950 for various computers at Birkbeck College.
High-level languages allow the programmer to write programs in terms that are syntactically richer, and more capable of abstracting the code, making it targetable to varying machine instruction sets via compilation declarations and heuristics. The first compiler for a programming language was developed by Grace Hopper. When Hopper went to work on UNIVAC in 1949, she brought the idea of using compilers with her. Compilers harness the power of computers to make programming easier by allowing programmers to specify calculations by entering a formula using infix notation (e.g., Y = X*2 + 5*X + 9) for example. FORTRAN, the first widely used high-level language to have a functional implementation which permitted the abstraction of reusable blocks of code, came out in 1957. In 1951 Frances E. Holberton developed the first sort-merge generator which ran on the UNIVAC I. Another woman working at UNIVAC, Adele Mildred Koss, developed a program that was a precursor to report generators. In Russia, Kateryna Yushchenko developed the Address programming language for the MESM in 1955.
The idea for the creation of COBOL started in 1959 when Mary K. Hawes, who worked for Burroughs Corporation, set up a meeting to discuss creating a common business language. She invited six people, including Grace Hopper. Hopper was involved in developing COBOL as a business language and creating "self-documenting" programming. Hopper's contribution to COBOL was based on her programming language, called FLOW-MATIC. In 1961, Jean E. Sammet developed FORMAC and also published Programming Languages: History and Fundamentals which went on to be a standard work on programming languages.
Programs were mostly still entered using punched cards or paper tape. See computer programming in the punch card era. By the late 1960s, data storage devices and computer terminals became inexpensive enough that programs could be created by typing directly into the computers. Frances Holberton created a code to allow keyboard inputs while she worked at UNIVAC. Text editors were developed that allowed changes and corrections to be made much more easily than with punched cards. Sister Mary Kenneth Keller worked on developing the programming language, BASIC which she was a graduate student at Dartmouth in the 1960s. One of the first object-oriented programming languages, Smalltalk, was developed by seven programmers, including Adele Goldberg, in the 1970s. In 1985, Radia Perlman developed the Spinning Tree Protocol in order to route packets of network information efficiently.