IBM 026 Card Punch
IBM 2501 Card Reader
Until the mid-1970s, most computer access was via punched cards. Programs
and data were punched by hand on a key punch machine such as the
IBM 026 and fed into a card reader like
the IBM 2501. Large computing sites such as
Columbia University purchased cards by the truckload and furnished them free
of charge to users. During the IBM 360 era (1969-80) Columbia's cards were
embossed with the legend "CUCC 360" (Columbia University Computer Center IBM
360) and the Columbia shield (In Lumine Tuo Videbimus Lumen).
Here is a pink "job card" (the first card in a deck), preprinted with the
essentials of Job Control Language (JCL) job-card syntax. Cards were
available in assorted colors, allowing color coding of different sections of
a deck such as JCL, program source, data. From the collection
of Joe Sulsona.
The punches are interpreted across the top line of the card; this is a
feature of the key punch and it works as long as there's a good ribbon. OS
JCL Job-card fields are preprinted on the card. Columns 73-80 are reserved
for sequence numbers, which can be used by
a sorter to put a deck back in order after it has
been dropped.
Here is a card punched on keypunch that either had no interpreter, or a
broken one, or whose ribbon was dry.
The diagonal cut on the upper left facilitates proper orientation of
the card (if the card is fed into the reader upside down or face down the
data will be misinterpreted). When all the cards in a deck of the corner
cut, misoriented cards will stick out.
Here's another customized card (without punches), this one from the
University of Karlsruhe (Germany) Computer Center, courtesy of Michael
Hartmann, Technische Universität München:
Early Punched Card Equipment, 1880-1951, Emerson W. Pugh and Lars Heide,
IEEE Global History Network Significant Technological Achievement
Recognition Selections (STARS).