How the Index Card Cataloged the World (2017)
10 comments
·March 6, 2025runjake
nsriv
I have only just relented to buying B6+ softcover notebooks for the slightly more room and longer form writing, but the hPDA served me very well for 15 years. Shuffling cards to bring them to the fore has become such an ingrained productivity trigger for task switching over the years.
WillAdams
Has anyone else ever encountered 3x5 cards which are punched and numbered along their perimeter?
Saw such a setup once where for each number was assigned a categorization different from the ordering, and for a given card, the matching hole would be opened up, then when searching a set of cards a rod would be inserted at the hole in question and lifted up and jostled, causing the matching cards to be revealed for inspection.
Unfortunately, didn't think to ask if was a product, or a mechanism devised by the owner's parent....
zabzonk
Yep, I've used these a long time back when I was a microbiologist, for categorising bacteria. Using two rods meant you could do an AND search in one operation. Also, if you clipped the wrong hole, you could fix it with Sellotape. I can't remember what they were called though.
Fun to be reminded of them!
yesfitz
https://en.wikipedia.org/wiki/Edge-notched_card
"Needle Card", "McBee Card", "Indecks", "E-Z Sort", "Cope-chat", "Keysort", "Flexisort", "Velom card", "Rocket card", "Slotted card" and variations on those all redirect to that article[1].
1: https://en.wikipedia.org/w/index.php?title=Special:WhatLinks...
EvanAnderson
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=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.)
dtagames
TIL that Carl Linneaus invented the 3x5 card. Good stuff.
cjohnson318
TIL playing cards were printed with a blank reverse side that people used for scrap paper, lottery tickets, business cards, birth/death announcements, etc.
I still carry a "Hipster PDA"[1] around, binder clip and all. Said binder clip came out of a box from the 1970s.
It's immensely useful in a pinch, it's free form, and I can place it flat on a surface and write on it.
And, if I write sensitive information on a card, unlike a regular pocket notebook, I can store it or take a secure photo of it and physically pitch that index card.
Thanks, Merlin Mann[2].
1. https://en.wikipedia.org/wiki/Hipster_PDA
2. https://news.ycombinator.com/user?id=merlinmann