A-0 System Explained

The A-0 system (Arithmetic Language version 0) was an early^[1] compiler related tool developed for electronic computers, written by Grace Murray Hopper^[2] in 1951 and 1952 originally for the UNIVAC I.^[3] The A-0 functioned more as a loader or linker than the modern notion of a compiler.^{[4] [5] [6]} 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 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,^[7] A-3 (released as ARITH-MATIC), AT-3 (released as MATH-MATIC) and B-0 (released as FLOW-MATIC).

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.^[8] 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.^[9]

See also

• History of compiler construction

Notes

1. Web site: List of early compilers and assemblers .
2. Book: Ridgway. Richard. Proceedings of the 1952 ACM national meeting (Toronto) on - ACM '52 . Compiling routines . 1952. 1–5 . 10.1145/800259.808980 . 9781450379250 . 14878552 . free.
3. Hopper "Keynote Address", Sammet pg. 12
4. Hopper. Grace. Keynote Address. 10.1145/800025.1198341 . Proceedings of the ACM SIGPLAN History of Programming Languages (HOPL) conference, June 1978 .
5. Web site: Bruderer. Herbert. Did Grace Hopper Create the First Compiler? .
6. Strawn . George . Strawn . Candace . Grace Hopper: Compilers and Cobol . IT Professional . 2015 . 17 . Jan.-Feb. 2015 . 62–64 . 10.1109/MITP.2015.6 .
7. • Sep 1955 . PAPERS: Automatic Programming: The A 2 Compiler System -- Part I . Computers and Automation . 4 . 9 . 25–29 . 2020-09-05.
   • Oct 1955 . PAPERS: Automatic Programming: The A 2 Compiler System -- Part II . Computers and Automation . 4 . 10 . 15–27 . 2020-09-05.
8. Book: Ceruzzi, Paul . A History of Modern Computing . registration . The MIT Press . 1998 . 9780262032551 .
9. Web site: Heresy & Heretical Open Source: A Heretic's Perspective .

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

1. Hopper. Grace. The Education of a Computer. Proceedings of the Association for Computing Machinery Conference (Pittsburgh) May 1952. May 1952. 243–249. 10.1145/609784.609818.
2. Hopper. Grace. Automatic Coding for Digital Computers. High Speed Computer Conference (Louisiana State University) February 1955. Remington Rand. 16 February 1955 .
3. Hopper. Grace. Keynote Address. Proceedings of the ACM SIGPLAN History of Programming Languages (HOPL) conference .
4. Ridgway. Richard K.. Compiling Routines. Proceedings of the 1952 ACM national meeting (Toronto) ACM '52. 1952 .
5. Book: Sammet, Jean . Programming Languages: History and Fundamentals. Prentice-Hall. 1969. g. 12.