[excitom]

Back in the day, I used punch cards in college computer courses. Languages like FORTRAN, COBOL, and assembler were column dependent, e.g.

Col. 1 : Blank, or a "C" or "*" for comments Col. 1-5 : Statement label (optional) Col. 6 : Continuation of previous line (optional) Col. 7-72 : Statements Col. 73-80: Sequence number (optional, rarely used today)

With the sequence numbers if you dropped the deck and scrambled the cards, feed the pile through a card sorter machine to put them back in order. If you didn't bother with sequence numbers, another technique was to use a magic marker to draw patterns on the side of the deck to help with resorting it if you dropped it.

[woofyman]

I never bothered with sequence numbers. Boy was it a joy to put your card deck in the reader and wait at the self serve printer, and have your program compile, run, and produce the correct output the very first time !