3 ms·

The worst nightmare. Worse than any horror movie you have ever seen. The thing about punch cards is that they were a sequence! Think of any program you have eve

The worst nightmare. Worse than any horror movie you have ever seen. The thing about punch cards is that they were a sequence! Think of any program you have ever written - the bigger the better - and put each line of typing on a separate card. These cards, no matter how many, are of absolutely no value unless they are in the correct sequence. Think about that. When I was learning to program we had decks of cards. Each deck was wrapped in between 10 and 20 rubber bands because the very last thing you wanted was to spill the cards on the floor. One time I went into the little room where you submitted your job - a stack of rubber-banded punch cards - by placing it on the desk. Then you waited until it "ran" and they gave you back your stack. Some guy came in and placed a deck, maybe 200 cards, on the desk, but WITHOUT any rubber bands. The five of us who were waiting for our jobs to run took one look at that stack without rubber bands. Each of us turned a deathly shade of pale and quietly left the room. None of us could stand even the thought of that stack of cards falling over.

codewench 3y ago
That's why you took a marker and drew a diagonal line along the side of the stack, so you could visually line then back up if anything happened. I mean, it wasn't great, but it was better than nothing
- wanderingstan 3y ago
  Exactly. Related: I wrote a blog post about the evolution of the developer experience a few years ago, including that tidbit: https://wanderingstan.com/2020-02-04/the-evolution-of-developer-experience-in-the-20th-century https://wanderingstan.com/2020-02-04/the-evolution-of-develo...
- tinus_hn 3y ago
  Exactly the same as what you do with a tray of photographic slides, in case you drop them
- euroderf 3y ago
  Altho of course as you modified your program, the cards got out of sync with the diagonal. I wonder if there was a technical term for this...
- robin_reala 3y ago
  My tutor at uni told us about how he’d learnt to do that after tripping over the step into the batch processing room and having to spend a couple of hours carefully reorganising that evening’s program.
analog31 3y ago
... unless you programmed in BASIC, where the line numbers enforced the sequence even if the cards were out of order. My first programming class used a machine that duplicated the physical layout of the IBM keypunch, but had a 1-line vacuum fluorescent display, and stored the "cards" on an 8 inch floppy. It was edit-able! You handed your floppy to the person in the little room, and got back your printout later on.
litoE 3y ago
That is why programming languages used only the first 70 or so columns of each card. The last few columns were ignored and you could punch a sequence number. If you dropped your deck of cards you could take it to a sorting machine that could rearrange them in increasing order of the sequence numbers. The trick was to make your initial sequence number increase in steps of, say, 100. Then if you later had to insert cards in the middle of the deck you could use intermediate sequence numbers. This is also why the cards had one corner sliced off - you could immediately tell if a card was upside-down or flipped over.
- kevindamm 3y ago
  I never used punch cards in earnest but your story reminds me of when I learned programming with BASIC and had to number each line -- it helped to begin with incrementing by 10 so that some lines could be inserted later without having to retype the entire program

codewench 3y ago

That's why you took a marker and drew a diagonal line along the side of the stack, so you could visually line then back up if anything happened. I mean, it wasn't great, but it was better than nothing

wanderingstan 3y ago
Exactly. Related: I wrote a blog post about the evolution of the developer experience a few years ago, including that tidbit: https://wanderingstan.com/2020-02-04/the-evolution-of-developer-experience-in-the-20th-century https://wanderingstan.com/2020-02-04/the-evolution-of-develo...
tinus_hn 3y ago
Exactly the same as what you do with a tray of photographic slides, in case you drop them
euroderf 3y ago
Altho of course as you modified your program, the cards got out of sync with the diagonal. I wonder if there was a technical term for this...
robin_reala 3y ago
My tutor at uni told us about how he’d learnt to do that after tripping over the step into the batch processing room and having to spend a couple of hours carefully reorganising that evening’s program.

analog31 3y ago

... unless you programmed in BASIC, where the line numbers enforced the sequence even if the cards were out of order. My first programming class used a machine that duplicated the physical layout of the IBM keypunch, but had a 1-line vacuum fluorescent display, and stored the "cards" on an 8 inch floppy. It was edit-able! You handed your floppy to the person in the little room, and got back your printout later on.

litoE 3y ago

That is why programming languages used only the first 70 or so columns of each card. The last few columns were ignored and you could punch a sequence number. If you dropped your deck of cards you could take it to a sorting machine that could rearrange them in increasing order of the sequence numbers. The trick was to make your initial sequence number increase in steps of, say, 100. Then if you later had to insert cards in the middle of the deck you could use intermediate sequence numbers. This is also why the cards had one corner sliced off - you could immediately tell if a card was upside-down or flipped over.

kevindamm 3y ago
I never used punch cards in earnest but your story reminds me of when I learned programming with BASIC and had to number each line -- it helped to begin with incrementing by 10 so that some lines could be inserted later without having to retype the entire program