For those who weren't around back then, this is what I am talking about. Punch cards would be printed up with coded programs. The programmer would sequentially shove a whole stack of these coded cards (representing one program) into a computer to run a their program or simulation. If one little thing was wrong, the stack was essentially rendered useless. My dad worked at Argonne National Laboratory when everyone shared one of those computing behemoths to run their scientific programs. He was able to abscond with lots of trashed punch cards for me and thus my animation career was born.

If you are curious about the history of punch cards you can take a look here: http://www.cs.uiowa.edu/~jones/cards/history.html

P.S. after you read this, don't ever complain about the speed of your computer again!