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Autocoder is any of a group of assemblers for a number of IBM computers of the 1950s and 1960s. The first Autocoders appear to have been the earliest assemblers to provide a macro facility.[1]


Both autocoder, and the unrelated autocode, a term of the same era used in the UK for languages of a higher level, derive from the phrase automatic coding. This referred generally to programs which eased the burden of producing the numeric machine language codes of programs.[2] "Autocoding" is seen occasionally, and can refer to any kind of programming system. In some circles "autocoder" could be used generically to refer to what is now called a macro-assembler.[3]


The first Autocoders were released in 1955 for the IBM 702,[4] and in 1956 for the almost compatible IBM 705.[5] They were designed by Roy Goldfinger who earlier had worked on New York University's (NYU) NYAP assembler.[6][7] These machines were variable word length commercial machines, as were many of the computers for which an Autocoder was released.

Besides the 702 and 705, there eventually also were Autocoders for the IBM 1410 and 7010,[8] [9] IBM 7030 (Stretch), 7070/7072/7074,[10] [11] IBM 7080, [12] and the IBM 1400 series.[13]

Autocoder as implemented on the IBM 1401[edit]

Symbolic Programming System[14] (SPS), was the assembler offered when IBM originally announced 1401 as a punched-card-only computer. SPS had different mnemonics and a different fixed input format from Autocoder. It lacked Autocoder's features and was generally used later only on machines that lacked tape drives, that is, punched-card only.[15][16]

Autocoder coding sheet

1401 Autocoder[17][18] is the most well known Autocoder, undoubtedly due in part to the general success of that series of machines. Autocoder was the primary language of this computer, and its macro capabilities facilitated use of the Input/Output Control System which eased the programming burden. [19][20][21] Autocoder also had the ability to process code written for SPS.

The 1401 was available in six memory configurations, with 1400, 2000, 4000, 8000, 12000, or 16000 six-bit characters. The 8000-character model was the minimum needed to run Autocoder. A loadable object file, on punched cards or magnetic tape, could be produced on an 8000-character model which could then be run on a 4000-character machine.


The popularity of Autocoder inspired other assemblers. ‘’Easycoder’’ for the Honeywell 200, a computer similar to the 1401, resembled Autocoder. Other manufacturers sometimes built competing products, such as NCR's "National's Electronic Autocoder Technique" (NEAT).[22]

The Pennsylvania State University developed a "Dual Autocoder Fortran Translator" (DAFT) compiler for the IBM 7074 in the 1960s which made it extremely easy to write (within a single program) lines of autocoder instructions freely interspersed with lines of Fortran code. This allowed symbolic machine instruction level coding within a higher level Fortran program, which was especially useful for optimizing the speed of inner loops, or for making use of the IBM 7074's unusual decimal word architecture.[citation needed]

Bell Laboratories developed a program called "Peripheral Equipment Symbolic Translator" (PEST), which was a 1401 cross-assembler that ran on the 709/709x and accepted a subset of 1401 Autocoder.[16][23]

A copy of the source programs for SPS-1, SPS-2 and Autocoder was donated to the Charles Babbage Institute, University of Minnesota in 1985, by Gary Mokotoff, author of SPS and coauthor of Autocoder.[24]


  1. ^ Solomon 1993, p. 8.
  2. ^ Hopper 1955.
  3. ^ For an example see Allen 1981, p. 540.
  4. ^ Catalog of Copyright Entries. Third Series: 1956. Copyright Office, Library of Congress. 1957. p. 305. Retrieved 2019-08-23.
  5. ^ 705 autocoder system - manual of information (PDF), IBM Systems Reference Library (Second ed.), IBM Corporation, February 1957, 22-6726-1
  6. ^ Goldfinger 1956.
  7. ^ The Encyclopedia of Computer Languages Archived September 16, 2007, at the Wayback Machine
  8. ^ IBM 1410 Autocoder (PDF), IBM Systems Reference Library (Second ed.), IBM Corporation, February 1964, C28-0309-1
  9. ^ IBM 1410/700 Operating System (1410-PR-155) - Autocoder - 1410-AU-968 (PDF), IBM Systems Reference Library (Third ed.), IBM Corporation, November 1964, C28-0336-2
  10. ^ Reference Manual - IBM 7070/7074 Four-Tape Autocoder (PDF), IBM Systems Reference Library (Second ed.), IBM Corporation, April 1961, C28-6102-1
  11. ^ Reference Manual - IBM 7070 Series Programming Systems - Autocoder (PDF), IBM Systems Reference Library (First ed.), IBM Corporation, 1961, C28-6121-0
  12. ^ Reference Manual - IBM 7080 Programming Systems - 7080 Processor: Autocoder Language (PDF), IBM Systems Reference Library (First ed.), IBM Corporation, 1962, C28-6263
  13. ^ 7010: Weik 1964, p. 0160; 7030:"IBM Stretch (aka IBM 7030 Data Processing System)", "Compilers and Computers: Partners in Performance" (PDF); 7070: Tom Van Vleck, "The IBM 7070", A Third Survey of Domestic Electronic Digital Computing Systems, Martin H. Weik, "IBM 7070", Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland; 7080: [1]; 1400 series: [2], 1410 Autocoder (PDF).
  15. ^ Thelen, Ed. "IBM-1401". Retrieved 2020-03-05.
  16. ^ a b Van Vleck, Tom. "1401s I have known". Retrieved 2020-03-05.
  17. ^ Autocoder (on Tape) Language Specifications and Operating Procedures IBM 1401 and 1460 Program 1401-AU-037 (PDF), IBM Systems Reference Library (First ed.), IBM Corporation, November 1964, C24-3319-0
  18. ^ Autocoder (on Disk) Language Specifications IBM 1401, 1440, and 1460 (PDF), IBM Systems Reference Library (Third ed.), IBM Corporation, April 1966, C24-3258-2
  19. ^ IBM Corporation. Executive Guide to the IBM 1440 Data Processing System (PDF). Retrieved 2020-03-08.
  20. ^ Solomon 1993, p. 8
  21. ^ "Archived copy". Archived from the original on 2007-09-17. Retrieved 2007-03-18.CS1 maint: archived copy as title (link).
  22. ^ Weik 1964, p. 0202.
  23. ^ IBM Corporation (1962). Catalog of Programs for IBM Data Processing Systems KWIC Index (PDF). p. 248. Retrieved 2020-03-05.
  24. ^ Gary Mokotoff Collection of IBM 1401 Program Listings, 1959-1961


  • Allen, F. E., "The history of language processor technology at IBM", IBM Journal of Research and Development, 25(5), pp. 535-548 (September 1981). [3]
  • Goldfinger, Roy, "The IBM Type 705 Autocoder". Proceedings East Joint Computer Conf., San Francisco, 1956.
  • Hopper, Grace, "Automatic Coding for Digital Computers" in the High Speed Computer Conference, Louisiana State (1955) the High Speed Computer Conference, Louisiana State University, 16 Feb. 1955, Remington Rand, Inc., 1955. [4]
  • Salomon, David (February 1993). Chivers, Ian D. (ed.). Assemblers and Loaders (PDF). Ellis Horwood Series In Computers And Their Applications (1 ed.). Chicester, West Sussex, UK: Ellis Horwood Limited / Simon & Schuster International Group. ISBN 0-13-052564-2. Archived (PDF) from the original on 2020-03-23. Retrieved 2008-10-01. [5][6] (xiv+294+4 pages)
  • Weik, Martin H., A Fourth Survey of Domestic Electronic Digital Computing Systems,BRL Report No. 1227, January 1964 (Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland). [7]

External links[edit]