When I teach a class [note for new readers: I teach software for a Really Big Computer Company, my students are usually experienced programmers] once I get past the usual administrivia (including locations of fire exits, bathrooms, coffee and soft drinks, etc.) I ask the students to introduce themselves, telling a bit about their professional/technical background and their purpose in taking the course. I usually by telling them a bit about my background, describing myself as someone who learned how to program using punched cards. This usually evokes amused snickers and head-nodding from older members of the class and somewhat bemused looks of amazement from younger members. Sometime soon I expect a student will probably ask "What's a punched card?"
The punch card (which many people, with good justification, often called an "IBM card") lasted an entire century as a useful technology. The technology was invented by Herman Hollerith (inspired by Jacquard looms) as a means of tabulating. The specific problem he had set out to solve was that of tablulating census results. Manual tabulation of the 1880 census took years to complete and it was easy to see that the booming population would soon mean that census results could not be fully tabulated before it was time to begin counting population for the next one. The 1890 census was tabulated using Hollerith's cards and machines. (Hollerith did quite well financially from his efforts. In the 1920's his company was merged with others to form a new company: International Business Machines.)
So the punch card (or IBM card) existed for decades before computers came into widespread use (or even existed). Cards could store data. Cards could be used as turn-around documents. (Send the bill on a punch card so when it is returned with payment the card can be used to record that payment.) Cards could be sorted and counted and tabulated. But if you folded a card, it could not be used. If you stabled them, they could not be used. If you spindled them (i.e., pushed them down on a spike for temporary storage... something that clerks might do with paperwork) they could not be used. Users in general (and the pubic especially) had to be educated not to do things that would prevent the proper usage of a punched card; hence the printed message: Do not fold, spindle, or mutilate.
When computers came along it was a natural thing to use punch cards, a proven technology that had been around since the Victorian era, for input and output with these new-fangled computers. Thus, the punch card also began to be called the computer card... and those who felt alienated or oppressed by increasingly remote and bureaucratic social institutions, schools, businesses, government agencies, began to associate the punch card with the forces producing this alienation.
Student protesters were seen carrying signs at demonstrations I am a human being [or I am a student] ; do not fold, spindle, or mutilate. You could buy t-shirts bearing the warning Do not fold, spindle or mutilate.
Registration at school meant going around collecting a series of punch cards (in the school gymnasium along with hundreds upon hundreds of other students), turning them in at a certain desk and receiving another group of punch cards (usually labeled "PERMIT TO ATTEND CLASS" or some such) which served as your entry ticket to each course. We soon came to recognize the particular pattern of holes that meant our names... I can recall a time when we would place a card on the inside cover of a textbook and carefully fill in the pattern of holes with pencile and then claim that if we lost our book and a computer found it, it would know whose book it was.
Later, I learned to read Hollerith... that is, how to read what was punched on a card based on the holes... even if no English equivalent was printed on the card. When I was a computer operator at a university, and student had punched card output from a program, those cards would be punched by the card read/punch unit, but there would be no text equivalent to the punch holes unless the deck were to be "interpreted" (that is, run through a machine that would read the holes for each column and print the appropriate letter or number above that column. We used to like to pick up the uninterpreted decks of cards and read the author's name based on the pattern of hles punched in the first card. Students would be amazed. "How can you tell what that says?" And we'd just grin and say "You mean you can't read it the card? But it's so easy..."
We used to have a cruel joke we'd play on graduate students. (Actually, it was a sign that the student had been accepted by the staff; we didn't do this to people we didn't like.) A grad student might typically be running batch jobs that might comprise hundred -- even thousands -- of punch cards (mostly data) that were carried around in card boxes. Blank cards -- the typical card was an IBM 5081 card, 80 columns = 80 characters, with rows of tiny preprinted numbers on the card, a row of all 1's, a row of all 2's, etc. -- came in boxes of two thosand cards. The students would reuse these boxes to hold their decks of cards, the cards held into large groups by rubber bands, and the boxes held closed by rubber bands. (Computer shops used to use thosands of rubber bands... and we would have some great rubber band fights in the computer room late at night.) The grad students would mark the tops of their card decks with marker pens into various sections: JCL, program code, input data, etc. Students would set their precious cards on our input window to be run. We would feed their decks into the card reader, rubber band them back together, and put them on the counter of an output window. Sometimes we would slip out of sight, set their cards safely to one side, and replace them with void cards leftover from processing library circulation runs, mark them up with marker pens so they looked like the student's cards, put them in their boxes without using rubber bands... and then place them on the output shelf so that they fell off the shelf and hit the floor, sending thousands of cards spewing out across the student setup area. The look of horror... hours and hours, perhaps weeks of work, scattered randomly across the floor.
Cruel? Yes... and sometimes we had to quickly produce their real deck of cards to prevent a total emotional meltdown... But, as I said, this really indicated that they had been accepted by the operations staff into an inner circle... and after this, they could ask for favors, have a job moved up a bit in priority on a busy night, be allowed to come in and use a keypunch machine in the computer room, invited to join the operators in ordering pizza to be delivered to the loading dock area under the computer center (otherwise deliveries were only made to dormitory lounges), to have a cup of coffee that was not from a vending machine...
And then punch cards began to disappear... keypunching became known as dataentry... and data was keyed in to disk files rather than on physical cards...
My previous employer was still using punchcards even in '94 for certain job runs precisely because of the punch card's versitility as a turn-around document. The machine manufacturer had long ago dropped maintenance and we had to use a third-party maintenance outfit that used buy up old card readers and canibalize them for parts. Finally we got all of those jobs replaced with barcoding.
And now the punch card's century is over... and there are thousands upon thousands of computer professionals who have never even held a punch card let alone used one. I'm sure I could still easily read numbers by looking at the pattern of punched holes but I doubt that I could decipher the letters of alphabet without painstakingly figuring them out one by one.
Hey, and blank 5081 cards were great for jotting down notes... just use the blank side... they fit in shirt pockets or hip pockets... just the right size for To Do lists or grocery lists... I miss them.