A punch card that works

Eighty columns of an IBM 5081, twelve rows each. Punch the holes and the character prints along the top, the way a keypunch interprets a card as it goes through. It arrives spelling HOLLERITH in the first ten.

Print at 100 percent, not scaled to fit. The card is 7 3/8 by 3 1/4 inches.

How it works

Each hole is a checkbox, and the decoding is done by CSS asking each column which of its own boxes are ticked. Sixty rules, one per character, generated from the IBM 029 keypunch table.

Rows 12 and 11 at the top are the zone punches, which is why they carry no printing. A letter is a zone plus a digit, so A is 12 and 1, J is 11 and 1, S is 0 and 2. Digits are a single punch. Everything else is a combination involving row 8, which is why the punctuation looks arbitrary until you have the table in front of you.

Print it and it comes out at the size of the real thing, corner cut and all.