Pink 80-column punch card with rounded corners and a card cut on the top left hand corner. Printed vertically in place of card columns 78-79 the card reads “6000 Scope Binary Card”. This indicates this card was for use with a Control Data Corporation 6000 Series computer, the operating system for which was called the Supervisory Control of Program Execution (SCOPE).
“University of London Computer Center” is printed in the left and right margins. Control Data Corporation (CDC) employee Gordon Hilliard recalls that the University of London Computer Centre had a CDC 6600 in 1970, and later purchased an additional CDC 6400.1 Photos of a processor card of the University of London’s CDC 6600 can be seen in the collection of Eric Foxley . As of 2024 this card of the is in the possession The National Museum of Computing, Bletchley Park, United Kingdom.2
The bottom margin of the card reads “PDC-3803” and each column is labelled under the 9 row, and at the top of the card in place of the 12 row. The card is divided into 15 fields of 5 columns between columns 3 and 77 . Each field can represent 60-bits, a word in the CDC 6000 series architecture.3 Every field is labelled with a large number beginning at 1 above the 0 row. Columns 1, 2 and 80 on the card are reserved for a series of special functions.
Column 1 contains two fields labelled “CHK” and “SUM WORD COUNT”. Column 1, rows 7 and 9 are punched on all specimens of these cards and the area behind these locations is shaded on the card, indicating that these positions were likely always required to be punched. The area labelled “SUM WORD COUNT” appears to be punched with the binary count of the number of words punched on the card.
Column 2 houses a checksum value for the card, which is labelled “CHECKSUM (IF CHK = 0)”. This indicates punching the “CHK” field in Column 1 appears to have disabled the checksum feature related to this card. Column 80 appears to have a special purpose and is punched on all specimens of this card, however, its purpose is not clear.