Wednesday, December 21, 2011

Punch cards

Babbage's punch cards
Science Museum, London
Most people today don't remember punch cards, but for decades they were an important means of programming computers. Though I never used them, my first computer lab still had card punch machines and card readers, and some "old timers" still used them. Charles Babbage first thought of using them for his Analytical Engine, both to input programs and store data. He got the idea of course from the Jacquard Loom that used punch cards to input complex lace designs into lace weaving looms.
    Though not used by modern computers, punch cards are still used by knitting machines to input designs, as you can see from the card below.