Columbia University Computing History   

The IBM 029 Key Punch

IBM 029 Punch
Photo: IBM 29 Card Punch Reference Manual, A24-3332-1, 1960.
IBM 029 card punch
Another view
The IBM 29 Card Punch (also called the 029 or Type 029 Key Punch or Keypunch), introduced about 1964 to coincide with the introduction of the IBM 360. Available in nine models with various combinations of keyboard (12-key numeric or 64-key alphanumeric), zero insertion, printing, and interpreting, and also as the IBM 59 Card Verifier (for verifying that cards punched on the 29 were correct).

IBM 029 numeric keyboard
Numeric keyboard
IBM 029 numeric keyboard

The alphanumeric ("combination") keyboard layout is shown in this diagram (Click to magnify to full size):

IBM 029 alpanumeric keyboard

Here's a card punched with each of 64 characters, showing the interpretation across the top:

IBM 029 card

If you magnify the keyboard diagram or card image, you can see the character set of the 029, which is similar to ASCII but lacks lowercase letters, includes two special characters not in ASCII ("not sign" (¬), needed for (e.g.) PL/I, and "cent sign" (¢), characteristic of the EBCDIC character set used by the IBM 360) [52] (for which the 029 was designed), and is missing several of ASCII's other characters: {}[]\^~

This is the first version of IBM's EBCDIC (Extended Binary Coded Decimal Interchange Code) character set. Although the repertoire of the 029 card punch is only 64 characters (sufficient to program in Fortran, PL/I, and Cobol), EBCDIC is an 8-bit set with a capacity of 256 characters. As terminals replaced card punches for data entry, lowercase latters, control characters, and other characters were added in the remaining space.

IBM 029 drum
IBM 029 program drum
The Program Drum, which allows "keyboard shortcuts" to be programmed for faster entry of certain kinds of data, e.g. Fortran source code, columns of numbers, etc. You could put up to two programs on one program card and switch between with the Program Select switch. The program defines fields to be automatically skipped, duplicated, or alpha-shifted. The program card turns in synchrony with the progress of the card through the punching station. The holes in the program card are sensed by little spring-loaded levers with tiny toothed wheels on the end. Heavily used key punches often had missing program wheels (and dry ribbons).

Here's a 1986 view of Columbia's last public keypunch, an 029 model (with a pair of DEC VT101 terminals to its left), in the picturesque SSIO Area:


In 1971, IBM announced its last key punch, the 129, which was an 029 with buffer memory, allowing data to be entered, checked, and edited before committing it to the card; storing up to six different formatting programs (equivalent to program-drum cards); and able to accumulate counts and totals. CLICK HERE for a photo from a 1971 IBM advertisement, and HERE for a higher-resolution (2.5MB) scan of whole ad.

  1. IBM 29 Card Punch Reference Manual, A24-3332-1 (February 1965).
    (The figures on this page come from this manual, except for the Columbia SSIO photo).
  2. Mackenzie, Charles E., Coded Character Sets, History and Development, Addison-Wesley (1980).

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Columbia University Computing History Frank da Cruz / This page created: January 2001 Last update: 26 March 2021