Edge-notched cards: stacks of papercraft hypertext

Kevin Kelly brings us an extraordinary reminiscence of the not-entirely-defunct (?) "edge-notched card," a punchcard hypertext technology that inspired visionaries and weirdos for decades before the PC came along.
Edge-notched cards were invented in 1896. These are index cards with holes on their edges, which can be selectively slotted to indicate traits or categories, or in our language today, to act as a field. Before the advent of computers were one of the few ways you could sort large databases for more than one term at once. In computer science terms, you could do a "logical OR" operation. This ability of the system to sort and link prompted Douglas Engelbart in 1962 to suggest these cards could implement part of the Memex vision of hypertext.
Link (Thanks, Daniel!)


  1. This technique was used by a gimmicky Role Playing Game record keeping set. The interior of the cards were a fairly standard D&D style character sheet. There were punch tabs along the edges for categories like Fighter and Elf. The set came with a sort of big safety pin that was used to hook out matching cards.

  2. We made our own version of these at school when I was 9 yrs old.

    As I remember we put things like hair and eye colour on them and then sorted a school year of about 90 kids.

    Great fun (and obviously memorable as it was more than 30 years ago).

  3. Any logical operation you like, actually.

    A modern electronic equivalent of this might be Content Addressable Memory, a specialized type of memory sometimes used in network routers.

  4. The multi-term selection isn’t a logical OR- using more than one needle in a single selection would be an AND operation; an OR would require combining several selections from the main set.

    As PFH points out, all other operations are possible by various combinations of selections; these are left as an exercise for the reader.

  5. Actually, I take it back about the multi-term selection not being a logical OR; thinking about it a bit more, this depends on whether it’s the slot coding 1 and the hole coding 0, or the other way round…

  6. Indiana University used multi-part cards like this back in the early 1980s for checking out books. Patrons had to fill out a card for each and every book they borrowed, complete with name, address, call number, title, etc.– very time-consuming! The smart ones took home piles of cards and typed their personal info on them in advance. Edges were notched to show due dates. Stick a rod through that date hole, and what fell out was due that day. IIRC, one of the carbons was mailed to the patron as an overdue notice. Not sure when they were phased out.

  7. I read legendary ad man and marketing guru Lester Wonderman’s book Being Direct a decade ago and had the privilege of having dinner with him after a keynote address at a Web marketing conference. (The attendees didn’t get his very good advice.)

    He wrote in his book that an early rose-by-mail retailer used punch card sorting to handle customizing the direct mail. I ask him about that, and he said that there were very long rods (not the chopstick lengths shown in the photo) to create selects, and that this was the first database-driven direct mail campaign he was aware of. Me, too.

  8. I recall my first elementary school’s administration using this technology. I also recall that sometimes the punch edges didn’t punch clean, causing a hang, and sometimes the punch edge tore out.

  9. Photo-Lettering Inc. used a system like this starting in the late 1950s in order to select fonts from its huge library based on a wide array of font characteristics. A similar digital system is built into the TrueType spec, but a lot of font developers don’t use it (or don’t know how to use it).

  10. Librarians still use the term “false drops” to indicate what people more commonly call “false hits”.

    After sliding one or more pins through the cards (through the notches appropriate to subject, author, or whatever), you’d lift up your pins and give them a shake. What dropped loose were supposed to be the results matching your search. Sometimes, though, the wrong notches were punched on the sides, resulting in “false drops”.

  11. We have a tree identification deck that uses this this system.

    You put your pin through the evergreen or deciduous hole and shake out the ones you don’t want. Then you pick bark type, then you pick leaf/needle shape. It works really well and is nice and portable. I guess there’s a palm pilot program that’ll do this, but I like the hands on out-in-the-open nature of this system.

  12. There used to be a big steel cabinet full of these cards in one of the back rooms at the Academy of Natural Sciences in Philadephia (USA). I think it was an entomology database but I am honestly no longer sure. Thousands of cards though.

    You could run these yard-long steel needles through the tops of the drawers and make various sorts of boolean queries. I thought it was pretty awesome, except for the fragility of the cards themselves.

    If the cards had been made of thin bronze, that’d be a database for the ages, eh?


  13. I built a set of these for myself in the late ’70s or early ’80s to track books I was interested in, by category. (It would be a few years before I would be able to afford a computer.) Thing is, they’re a lot of work to fill out and set up. You need to have a reason to search them regularly before it pays off.

  14. The modern version was called Abney (or Abby?) cards, I believe. I have seen the commercial set (with punch, giant safety pin). I made my own for my dissertation with colored markers on 3 by 5 or 4 by 6 cards.

    Variations on this are diagonally swiping the top of a box of Hollorith cards with a marker so when they get dropped, the cards can be put back in order.

    Ditto for 35mm slides for a presentation.

  15. #15– bronze would be a good choice except that the prices for metals these days results in a new definition of grave robbing (bronze and brass plaques and memorials)

  16. Vespabelle, can you tell me where you got those Tree Sort Guide punched cards?

    I’ve tried Amazon, Carolina Biological Supply, Wards Scientific, Acorn Naturalists, Forestry Suppliers -nobody’s got them!

    Thanks for any advice you can provide.

Comments are closed.