A-0 System

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]

  1. ^ "List of early compilers and assemblers".
  2. ^ Ridgway, Richard (1952). "Compiling routines". Proceedings of the 1952 ACM national meeting (Toronto) on - ACM '52. pp. 1–5. doi:10.1145/800259.808980. ISBN 9781450379250. S2CID 14878552.
  3. ^ Hopper "Keynote Address", Sammet pg. 12
  4. ^ Hopper, Grace. "Keynote Address". Proceedings of the ACM SIGPLAN History of Programming Languages (HOPL) conference, June 1978. doi:10.1145/800025.1198341.
  5. ^ Bruderer, Herbert. "Did Grace Hopper Create the First Compiler?".
  6. ^ Strawn, George; Strawn, Candace (2015). "Grace Hopper: Compilers and Cobol". IT Professional. 17 (Jan.-Feb. 2015): 62–64. doi:10.1109/MITP.2015.6.
  7. ^ * "PAPERS: Automatic Programming: The A 2 Compiler System -- Part I". Computers and Automation. 4 (9): 25–29. Sep 1955. Retrieved 2020-09-05.
  8. ^ Ceruzzi, Paul (1998). A History of Modern Computing. The MIT Press. ISBN 9780262032551.
  9. ^ "Heresy & Heretical Open Source: A Heretic's Perspective".