Tristan Davey's Punch Card Archive

The term used in those days was 'computer'!

https://en.wikipedia.org/wiki/Computer#Etymology

> It was not until the mid-20th century that the word acquired its modern definition; according to the Oxford English Dictionary, the first known use of the word computer was in a different sense, in a 1613 book called The Yong Mans Gleanings by the English writer Richard Brathwait: "I haue [sic] read the truest computer of Times, and the best Arithmetician that euer [sic] breathed, and he reduceth thy dayes into a short number." This usage of the term referred to a human computer, a person who carried out calculations or computations. The word continued to have the same meaning until the middle of the 20th century. During the latter part of this period, women were often hired as computers because they could be paid less than their male counterparts. By 1943, most human computers were women.

There are two books you should take a look at.

"Methods of Information Handling", Charles Bourne - https://archive.org/details/methodsofinforma0000unse/page/n5... (not available to read)

"Punched Cards: Their Applications to Science and Industry", https://archive.org/details/punchedcardsthei0000robe (can be checked out)

The first of these is a much better book.

They show a number of ways to encode values, such as a 5-hole triangle code, where the "O" in the following indicates a hole:

    O   O   O   O   O
      9   5   2   0
        8   4   1
          7   3
            6

To encode the value "8", notch out the holes (indicated with "U") which cross to 8 (indicated with "\" and "/"), like this:

    U   O   U   O   O
     \9   5/  2   0
       \8/  4   1
          7   3
            6

This lets you encode 10-digit values with 5 holes and two needles -- remember, inserting the needles takes time. (And there were all sorts of devices made to minimize that time.)

There were also extensions of these to handle names, used to search small (< ~10,000) literature collections, and more.

The most mathematically sophisticated is likely Zatocoding, a superimposed coding method related to Bloom filters.

The Bourne book goes into these variations in detail.

Here's a video of someone scanning in edge-notched cards for bird identification. https://youtu.be/MBwP3YOxw3I

About 10 years ago I really go into the topic and made some cards of my own, using a cutting machine to make each card, precut, from an SVG.

You could also use Zatocoding, or superimposed codes (https://en.wikipedia.org/wiki/Superimposed_code) as a way to 'tag' cards.

For example, many research facilities kept a stack of edge-notched cards as a way to find papers to read. You write the name of a paper or book on a card, and you notch out the holes which correspond to a search term, like 'polymer', or 'cellulose' -- then you can use needles in those holes to search for them later.

You can also then do things like boolean searches. Let's say you want all of the papers which are about polymers which are not cellulose. First you poke the holes for 'polymer', and collect up all the ones that drop. Next you take that stack and poke the holes for cellulose -- the cards which drop are about cellulose, so you ignore those, and the ones left on the needles are about polymers which are not cellulose.

I got really into the idea of doing this as a way to do something like a crazed zettelkasten, and reading material from the time this was widely used they would claim they could sort through thousands of cards in a few minutes. Not as quick as ripgrep, but not too shabby.

The s390x Linux install under z/VM boots from a virtual card reader, from cards generated by a virtual card punch from the installation files.