Here's a good video of an obsolete technology - a punched card reader.[1] No voice over. No intro. No outro. No clickbait. Just a beautifully clear demonstration of what it is and how it works.
Wanna know what another obsolete object is, a real one, no longer made and with no functional use anymore?
An lubricant oil can spout.
We stopped selling lubricating oil in cans like at least 35 years ago.
I have vague memories from my childhood of seeing cans of oil stacked in a store, but I can't tell if its a hallucination or memory, or something I actually saw, it would have been when I was very young based on the perspective I can recall them at.
(edited to add the word lubricant)
https://www.odysea.com/product/odysea-greek-extra-vrigin-oli...
https://www.ebay.com/itm/134826590749
Here is an example of what one looks like.
Some additional context - https://www.latimes.com/archives/la-xpm-1985-02-10-fi-3748-s...
No, it's still common, but used more in industrial settings. Most machine shops and auto shops will have such a can in easy reach.
I'm not talking about metal cans with a screw top or port on it, these were completely sealed, and you had to use an external opener which pierced the metal top.
All of the metal oil cans I've seen in machine shops are larger 5gal ones, that have a screw on port.
For anyone wondering why the card deck has the diagonal stripes on the edge, those are for when you drop the deck and have to put the cards back in order.
And don't get me started on TTS voice-overs! The first time I heard one, I actually thought for a few moments, "There is something wrong with this guy's voice." Then I figured it out.
But do the diagonal stripes actually work? If you dropped the deck and then re-assembled it with a single pair of cards swapped, would you really be able to catch that based on the stripe?
Listening to the machine work was incredibly interesting, too. I wonder how much stress it puts on the cards to be run through the machine each time. Did they have to make "fresh" copies once the cards got worn down by going through the machine too many times?
The blank cards I've seen had printing on one side, and usually some sort of title area. so you could get orientation correct.
The punched cards I've seen were all hand numbered.
The stripe, I think, was mostly a quick check. if it looks like a line, they're probably in order. if there's a spot that looks weird, you can check that range quickly.
I don't think the failure mode was like someone grabbing your deck and throwing it in the air, it was more they got dropped, stayed mostly stacked, but you could quickly file the strays in the right order. and be pretty confident the cards that stayed stacked were right. if you've got a blurry spot of the line, you can quickly check that section.
so, yes? I think the stripes worked? Again, before my time, this is lore handed down from professors. I think if you secretly swapped 2 cards, and they didn't notice, they would hunt you down and beat you up.
IIRC, the cards did wear down, but there were duplicators, that would read old cards and punch fresh ones. Obviously, if something was torn or damaged, you'd have to fix that by hand. I think I've seen one once, but I don't recall exactly where.
edit- https://en.wikipedia.org/wiki/IBM_519#514 <- that's not what I remember, but they did exist.
Less than almost every other card reader ever made, which is why that Documation unit took over the industry. The hard problem is pulling exactly one card off the bottom of the stack. Most previous readers involved some kind of pusher which had a ledge slightly less than one card thick. The pusher pushed the card through a gate slightly more than one card thick. The IBM 1402 card reader, and all the earlier IBM electromechanical card machines, used that technology.[1] Pushing cards through a gate works only if cards are within tolerance and in good condition. Otherwise, card jams are frequent. Card data processing operations had dehumidifiers, because high humidity would make the cards thicker.
Documation made a breakthrough. There's a crosswise air jet that separates the bottom few cards in the stack before picking. The video shows that. The picking device itself is a vacuum picker. It grabs the bottom card, rotates, and starts the card into the rollers. The card is always pulled by a face, never pushed by an edge. Card thickness does not matter much. It just works.
That air jet trick is still used in some printers and printing presses. It's one of those clever tricks of mechanical engineering that yields a simple, reliable device.
Interesting that the nameplate clearly documented its current draw at startup and while running (1/3 the startup).
That tells you that the device needs to be on a circuit with a slow-blow fuse or circuit breaker. Motors draw more current during startup. Look up "inrush current" and "motor protection circuit breaker".
(Starting AC electric motors is surprisingly difficult. Tesla's big contribution to electrical technology was figuring out how to start AC motors simply, cheaply, and reliably.)