My mum was a programmer (although that wasn't the term) back in the age of punch cards.

I don't know how people programmed during this time. There was at least a day between handing something in and getting the results.

I can't imagine the frustration of finding out you did whatever the equivalent of missing a semi-colon out was.

My mum has a different disposition to me, I don't think I'd have survived as a programmer back then.

Those edge-notched cards for mechanically searching are amazing! I guess you could enter a binary number with several needles to instantly pick out a single card from a deck of thousands.

I have a child's puzzle game that works the same way. You poke a pin through a hole in the deck holder to choose your answer, then try to pull the card out. It won't come out unless you poked the correct hole.

By the way, punched cards live on in virtual form as text file formats used by engineers everywhere for popular products like Abaqus and Nastran. There are actual engineers today operating software by typing text into fields lined up by the column number of the card in a similar way to how they would have punched the cards in the old days but usually with some automatic card generating pre-processor to help with the tedious parts. They even use the jargon of cards and decks when they're actually lines and files today.