The A-0 system (''Arithmetic Language version 0''), written by

Grace Murray Hopper Grace Brewster Hopper (; December 9, 1906 – January 1, 1992) was an American computer scientist, mathematician, and United States Navy rear admiral. One of the first programmers of the Harvard Mark I computer, she was a pioneer of com ...

in 1951 and 1952 for the

UNIVAC I The UNIVAC I (Universal Automatic Computer I) was the first general-purpose electronic digital computer design for business application produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the inven ...

, was an early

compiler In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs tha ...

related tool developed for electronic computers. The A-0 functioned more as a

loader Loader can refer to: * Loader (equipment) * Loader (computing) ** LOADER.EXE, an auto-start program loader optionally used in the startup process of Microsoft Windows ME * Loader (surname) * Fast loader * Speedloader * Boot loader ** LOADER.COM ...

linker Linker or linkers may refer to: Computing * Linker (computing), a computer program that takes one or more object files generated by a compiler or generated by an assembler and links them with libraries, generating an executable program or shar ...

than the modern notion of a compiler. A program was specified as a sequence of subroutines and its arguments. The subroutines were identified by a numeric code and the arguments to the subroutines were written directly after each subroutine code. The A-0 system converted the specification into

machine code In computer programming, machine code is any low-level programming language, consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). Each instruction causes the CPU to perform a ve ...

that could be fed into the computer a second time to execute the said program. The A-0 system was followed by the A-1, A-2, A-3 (released as

ARITH-MATIC :''You may have been looking for arithmetic, a branch of mathematics.'' ARITH-MATIC is an extension of Grace Hopper's A-2 programming language, developed around 1955. ARITH-MATIC was originally known as A-3, but was renamed by the marketing dep ...

), AT-3 (released as

MATH-MATIC MATH-MATIC is the marketing name for the AT-3 (Algebraic Translator 3) compiler, an early programming language for the UNIVAC I and UNIVAC II. MATH-MATIC was written beginning around 1955 by a team led by Charles Katz under the direction of Grac ...

) and B-0 (released as

FLOW-MATIC FLOW-MATIC, originally known as B-0 (Business Language version 0), was the first English-like data processing language. It was developed for the UNIVAC I at Remington Rand under Grace Hopper from 1955 to 1959, and helped shape the development of ...

). The A-2 system was developed at the UNIVAC division of Remington Rand in 1953 and released to customers by the end of that year. Customers were provided the source code for A-2 and invited to send their improvements back to UNIVAC. Thus, A-2 could be considered an example of the result of an early philosophy similar to free and open-source software.

Notes

External links

Proceedings of the 1954 MIT Summer Session on "Digital Computers - Advanced Coding Techniques, section 7 - A2 Compiler and Associated Routines for use with Univac

References

# # # # #{{cite book , last = Sammet , first = Jean , title = Programming Languages: History and Fundamentals, publisher=Prentice-Hall, year=1969, pages=g. 12 Procedural programming languages Programming languages created in 1951

See also

Notes

External links

References