IBM 96-column card
The IBM 96-column card was introduced in 1969 with the IBM System/3, and became fairly popular in the 1970s. While it had more columns than the 80-column IBM card, each column had only six punch positions (labeled, from the bottom up, 1, 2, 4, 8, A, and B) compared to the twelve positions of the 80-column cards, and punches were small and round; this allowed three rows of 32 columns to be fit on a 3 13/16" x 4 in. card. More efficient coding schemes were used here than on the 80-column cards, but it still allowed only for uppercase letters. The more compact cards could be used in places the older cards wouldn't fit, and turned up in such locations as tucked inside library books to note the due date, so that on checkin a card-reader could immediately note if it were overdue. One form of this card was designated IBM 3700. This had space for a fourth row of text in the human-readable print section at the top of the card (going up to column 128), presumably for labels of use to system operators but not actually used by the computer since there were no holes to punch for those positions.
References
- IBM 96-column card (Wikipedia)
- 96-column cards (Computer History Museum)
- Picture: 96-column card
- The Punched Card: shows details of a number of card formats and character encoding schemes
- Punched card emulator
- Vintagetech: company that specializes in recovering and converting old data including punched cards
