Punched Cards - For Computers

With the advent of computers, complex pre-formatted cards continued to be used for to hold data, but in addition, cards were printed with formats specific to the needs of programmers. Some of these were equal in complexity to the standard data processing cards.

The "IBM CALCULATOR INSTRUCTION CARD" shown here was printed in the early 1950's probably for use by programmers of the IBM 701, IBM's first general purpose computer. The card includes fields for both symbolic and numeric addresses, so it is probable that it was used with a rudimentary assembler that directly punched the assembled object code onto the cards holding the source code.

As programming languages grew more sophisticated, they shifted from fixed format to free format, and the preprinted material on cards began to shift to other functions. The card shown above is an assembly language card printed for Bell Labs, for the GE 600 computer they purchased in the mid 1960's as part of their work in the Multics project. This card contains a few fixed fields, but the artwork centers on a corporate logo, and to help programmers, much of the space on the card is devoted to documentation of the punch positions used for each character in the GE 600 character set.

With the widespread standardization of high level languages such as FORTRAN and COBOL, generic punched cards for those language were widely sold. These were almost entirely free-form languages, with only a few constraints on format, but the tradition of cards with clearly labeled fields lived on for a long time. The FORTRAN card shown here was printed by IBM's New Zealand office, but it is otherwise indistinguishable from millions of similar cards printed around the world.

As fewer and fewer users asked for cards with field markings specific to their applications, it became more and more likely that users would use cards purchased for one purpose for some other purpose. In open shops, such as university computer centers, this became a particular problem. Anyone could walk in off the streets and "borrow" an handful of cards. The solution was to order cards with custom printing to identify the institution! The card here is from one of the oldest computer laboratories in the world, the University of Illinois Digital Computer Labratory, home of the ILLIAC computers and builder of ORDVAC. This card has two sets of column indicators across the top, one for printing keypunches, which printed directly above the column being punched, and one for IBM's standard line of interpreters, which printed the first 64 columns on one line and the remaining columns on the line immediately below.

Of course, merely putting the name of the institution on the card is not very exciting, so many institutions, large and small, added corporate logos. Princeton University did this very nicely, as illustrated above. Princeton is noteworthy as the home of the Institute for Advanced Study, where, in 1946, John Von Neumann convened the Princeton Summer School and launched the computer age.

The graphic design work that goes into making special printing plates for a punched card can cost money, so sometimes, institutions opted for a less expensive route, overprinting a standard form with their logo instead of designing the form around the logo, as Princeton did. The MIT card shown above is a remarkably crude example of this, from an institution from which better would have been expected. In fact, this card was a stopgap measure while MIT was in the process developing a modernized logo.

A high resolution scan is available.

In the 1960's, IBM introduced a 128 column card, containing 4 rows of 32 character positions each, where each character position was punched using a 6-bit code. These cards, at 2 5/8 inches high by 3 1/4 inches wide, were significantly smaller than the original Hollerith cards, and they could boast 38 more characters of data per card than the old UNIVAC standard. These cards were introduced along with IBM's System 3 line of "small business" computers, and they were intended to displace 80 column cards from the market. Despite their obvious advantages, they never caught on outside of certain specialized applications, notably retail sales price tags and inventory management. The 128 column cards were also used with only 96 columns of punched data, leaving room for 4 rows of print along the top edge instead of the usual 3 rows.

Most users considered these to be 96 column cards because punching the 4th row, the top row, punched through the textual version of the data, making it difficult for people to read what was printed there; furthermore, by the early 1970's, there was a strong demand for support for mixed upper and lower case text; this required the switch from a 6-bit to an 8-bit code. In order to maintain compatability, the high 2 bits of the 8-bit code were punched separately from the low 6 bits, subdividing the top row of the card (formerly reserved for columns 97-128) to hold 3 tracks of 2-bit data instead of one track of 6-bit data. Clever code design ensured that old cards, punched using the 6-bit code, were correctly read using 8-bit software so long as the card did not contain more than 96 columns of data.

By the mid 1970's, most large scale data processing operations were at least investigating moving their punched card operations to timesharing environments, with their data stored on disk or magnetic tape, and by the mid 1990's, with timesharing mainframes and personal computers, the shift was almost complete, with very few businesses still using cards for anything other than scratch paper.

Curiously, while cards are becoming rare, you can still occasionally find price quotes for them. For example, the University of California at Davis Central Stores Online Catalog listed cards as recently as 1996:

   Catalog Item Number: 71510-109
    IBM CARD, BLANK TOP, LEFT CUT, 2000/BOX
      Also known as data processing or keypunch cards.
    Price: $42.085 per Box
    Prices are current as of: Mar 2 06:00 (1996)

One of the last important uses of punched cards has proven to be be voting. Use of pre-scored punched card ballots was introduced in the 1960's, and despite problems in the 1968 general election in Detroit, where a sudden rainstorm drenched at least one load of ballots in transit from a polling place to the counting center, this format quickly grew to become the most widely used computer-based election technology. By the time of the contested presidential elections of the year 2000, it was estimated that 1/3 of the polling places in the United States still used punched card ballots.

The problems with punched card ballots in the 2000 presidential election should not have come as a surprise. By the 1984 general election, the state of Iowa had effectively banned the use of punched card ballots, and in 1988, the Computer Professionals for Social Responsibility published a call for a general ban on the use of pre-scored punched card ballots (see http://www.cpsr.org/publications/newsletters/old/1980s/Fall1988.txt ). By the early 1990's mark-sense ballots and direct-recording electronic voting machines had both been developed to the point where they were viable replacements for punched card ballots, and in fact, by the year 2000, the major vendors of card based voting systems had all shifted their marketing emphasis to these newer technologies.