4 ms·
> Because cards were read "sideways" That is, cards were read row by row, not column-(character)-by-column — one ‘bit’ from every character at once. And this i
by kps 2y ago
> Because cards were read "sideways"
That is, cards were read row by row, not column-(character)-by-column — one ‘bit’ from every character at once. And this is the case for practically all card equipment. That surprised me a bit when I first learned it, as someone used to sequential character streams, but it makes sense in the context of pre-computer card operations, where cards and holes started and stopped counting wheels for each digit (column) at once to calculate totals.
- kens 2y agoThe IBM System/360 moved to card readers that operated column-by-column, e.g. the 2501 card reader or the 2560 Multi-Function Card Machine. As you said, reading row by row makes a whole lot of sense when you have electromechanical equipment. It's amazing that they could build things like card sorters without any electronics, just a brush and solenoids.