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.
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. 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).
Here's another example, this one from the University of Karlsruhe (Germany)
Computer Center, courtesy of Michael Hartmann, Technische Universität