Advent of Computing did an episode about edge-notched cards (and the host has an interest in them that goes beyond just this episode): https://adventofcomputing

Advent of Computing did an episode about edge-notched cards (and the host has an interest in them that goes beyond just this episode): https://adventofcomputing.com/?guid=4f6df5dd432d489db6d2a211bdb45403 https://adventofcomputing.com/?guid=4f6df5dd432d489db6d2a211... Douglas Englebart apparently used them and had devised his own filing system. (I don't recall if that's discussed in this or another episode.)