It’s likely that very few Irreal readers have ever used punch cards or maybe even know what they are. Nevertheless, they were once the mainstay of the computer industry. Indeed, IBM started out as a company that made punch-card-tabulating machines for the U.S. Census. If you’re really an oldtimer, you may even have called them Hollerith cards, named for the man who invented them and got the whole thing rolling.
In those days, there were no terminals or other interactive access to computers. Everything was batch and the way you input things—programs or data—was through punch cards. The last few columns of the card were theoretically reserved for sequence numbers but nobody ever used them for that. That led to many exciting experiences when a card deck containing your program or data was dropped and scattered on the floor.
Caleb Scharf over at Slate has an interesting article on punch cards and their role in our industry’s history. It’s based on his book The Ascent of Information: Books, Bits, Genes, Machines, and Life’s Unending Algorithm. The article doesn’t quite capture what it was like dealing with the cards and their periphery, such as key punches and card readers, but it does have lots of interesting details about the cards and their influence.
Scharf presses a connection between punch cards and biological processes that I find a little strained but the article is still interesting and worth a read if you’re interested in retrocomputing. It’s also worth a read if only to discover how easy we have it today. Believe me, a crashed disk or corrupted file system are way less common than a dropped card deck. And did I mention card readers regularly shredding cards? That gave rise to the universal sobriquet “card eater.”