Control Cards

Each deck of punched cards submitted to a computer center described one job for the computer to do. The deck might contain many sub-sections, perhaps a source program, perhaps an executable in binary format, and possibly one or more blocks of data to be input to the program. The entire deck would typically be headed by a job card, and each subsection would be introduced by one or more control cards.

Today, we speak of command-line interpreters such as the various Unix shells or Microsoft 's COMMAND.COM and its successors. IBM's 360 and 370 series of machines supported JCL, IBM's Job Control Language, and similar command languages existed for most computers. When input was from punched cards, the control cards held commands in the appropriate command language.

Many computer users simply punched command-language control cards on the same cardstock used for other material, but it was useful to punch them on a different color of stock in order to make it easy to separate programs or data from the cards that "glued" them together into a job.

• Generic EOF card
• Hummel 5477

• RWTH Aachen
• Universität Bremen
• Brown Boveri
• Leibnitz Rechenzentrum München
• University of London
• Thyssen AG

Generic EOF card

This end-of-file card is pre-punched in column 1 in rows 6, 7, 8 and 9, called a 6-7-8-9 multipunch; this marked and end of file for CDC's NOS operating system. Nothing in columns 2 to 80 on an end-of-file card mattered, so the 12-11-0-1 punch in column 80 is ignored. But note, if the card is turned 180° it will read identically as an end of file.

An unusual feature of this card is that it has color stripes not only on its top edge but also on the bottom. This means that if the card is turned 180°, a stripe will still be visible on the top of the card deck.

The card gives no hint of its manufacturer, but the figure 8 printed in column 1 appears to be printed by an IBM keypunch — the 5×7 dot-matrix font used was used on both the IBM 026 and 029 punches. This suggests that the card was punched on a keypunch, probably by setting the punch to duplicate column 1 only, and making two passes through a stack of cards, one for each orientation.

Hummel 5477

Hummel was a major card supplier in Germany. This Steuerkarte or control card, was among their offerings. Aside from the notation Steuerkarte, nothing about the design of this card is specific to its use for holding a line of some command language.

Note that Steuerkarte could also be translated "tax card," but that the German word Steuer has many other connotations related to control or steering.

RWTH Aachen

This Steuerkarte (control card) from the RWTH Aachen Rechenzentrum bears little resemblance to the Hummel 5477; the font used for the word Steuerkarte is quite different, and the body of the card has been divided into 20 4-column fields, despite the fact that no command language uses such field divisions.

Hummel printed this card.

The end-of-file card is pre-punched in column 1 in rows 6, 7, 8 and 9, called a 6-7-8-9 multipunch; this marked and end of file for CDC's NOS operating system. The end-of-record card has a 12-11-10-1-6-7-8-9 multipunch in column 1.

Hummel printed and may also have punched the end-of-file card.

Universität Bremen

The Universität Bremen Rechenzentrum (University of Bremen Computer Center) had these cards printed to mark the ends of jobs. In the IBM System 360/370 Job Control Language, end of file and end of job were both marked with a card containing the text /* in columns 1 and 2. In CDC's NOS operating system, the otherwise illegal character code made by punching rows 6, 7, 8 and 9, called a 6-7-8-9 multipunch, marked end-of-file. The notation END OF JOB does not commit the card to marking the end of a job, but if all users followed the convention of using yellow cards like this as end cards and for no other purpose, it simplified the job of computer operator.

Hummel printed the card.

Brown Boveri

Brown Boveri was a major Swiss manufacturer of heavy electrical machinery, founded in 1891. In 1988, it merged with ASEA to form ABB. This job control card, from the Brown Boveri Rechenzentrum (computer center) is formatted for two IBM System 360/370 Job Control Language commands, EXEC (execute) and DD (data definition). This card has been punched on its flip-side, which is formatted as a JCL job card. This card is similar to the Thyssen JCL card, but that card has all if its alternate formatting on one side.

Hummel printed the card.

Leibnitz Rechenzentrum München

The Leibnitz Rechenzentrum (computer center) in Munich is known today as the Leibnitz Supercomputing Centre, a branch of the Bavarian Academy of Sciences and Humanities. The TR 4 steuerkarte (control card) was designed for a TR 4 computer, an early model dating to the early 1960s. The TR 440 kommandokarte is for the successor machine used in the 1970s. TR stands for Telefunken Rechner (Telefunken computer).

University of London

The ULCC (University of London Computer Center) was founded in 1968, and began operations at 20 Guilford Street, London, with CDC mainframes providing computing services to all of the University of London's colleges. This job control card offers no advice about the layout of job-control commands, unlike many of the other job control cards shown here.

This card was printed by IBM United Kingdom.

Thyssen AG

This job control card from Thyssen AG has a marginal date of 10/79 in the upper right. Thyssen's corporate logo on this card is far smaller than necessary. The card itself is formatted for a number of different commands for the IBM System 360/370 Job Control Language. The topmost line on the card explains the initial format of a job card, while the other lines give guidance for the formats of other commands. The comparable card printed for Brown Boveri contained layout guidelines for only the two most common JCL statements.

This is one of the few job cards in the collection that suggests using the same color of card for both the job card and other cards that might be scattered through the card deck of a job.

This card was printed by Lochkarten-Service Essen.