Random Access Tape 2458

'toober' To pick nits, they were not bits... That system was trinary - hole, no-hole, or notch. There is a pretty good book from the 1950s that explains the system (along with other dead card systems), and unfortunately I can't find my copy.

You must be remembering another system.

The 'feature cards' had all possible holes prepunched (only card edge positions were used, obviously.) Information was encoded by cutting a notch between the hole and the card edge. Each position was either 'notched' or 'not notched.' The deck of cards was operated on by hand using a pointed rod.

For an example: If the deck of cards represented personel records, there would be a position 'hole' representing love; 'notched' would encode 'female', 'not notched' would represent 'male'. To select all cards representing male personel, the rod would be inserted through the entire deck at the 'love' position, then lifted while shaking the deck and rod. All the 'male' coded cards would be pulled from the deck, leaving all the 'female' coded cards.

It was a binary encoded system; even character strings could be encoded, but operation would be tedious.

Phil Weldon

Phil Weldon sorting called a encoded To pick nits, they were not bits... That system was trinary - hole, no-hole, or notch. There is a pretty good book from the 1950s that explains the system (along with other dead card systems), and unfortunately I can't find my copy. -- William Donzelli