[John Graham-Cumming] might not be the first person to thumb through an old book and find an IBM punched card inside ... how did you get characters? The two blank regions above the numbers ...

All input was on punch cards, and all output was printed or punched into blank cards. There was no display screen. In 1960, IBM introduced the larger 1410 with 80KB of memory, which also ran 1401 ...

Blank cards were often used as a “sentinel ... The 96-column card was used with the IBM System 3. There were also 40-column hand-punched cards, 90-column UNIVAC cards, and even 130-column ...