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(Among many others) I didn’t know what a lace card was so I had to look up: https://en.m.wikipedia.org/wiki/Lace_card https://en.m.wikipedia.org/wiki/Lace_card.
by Jun8 2y ago
(Among many others) I didn’t know what a lace card was so I had to look up: https://en.m.wikipedia.org/wiki/Lace_card https://en.m.wikipedia.org/wiki/Lace_card. How would you even make one? And it had to be cleared with a “card knife”!
- bunderbunder 2y agoYou use one of these: https://en.wikipedia.org/wiki/Keypunch https://en.wikipedia.org/wiki/Keypunch
- dfox 2y agoYou punch 80 columns worth of DEL. The card will jam the reader, but will get punched just fine.
- kens 2y agoSince I work with punch cards at the Computer History Museum, I can answer this. A standard IBM punch card has 80 columns and 12 rows, with each character represented by 1-3 punches in a column. A lace card has all the holes punched, so it's not punched with a normal card pattern. You can create a lace card, though, with a keypunch if you hold down the "multi punch" key. This lets you punch multiple times in a single card column, allowing you to punch patterns that don't have keys. So you could type &-0123456789 with multi-punch in each column to punch all 12 holes, which would be tedious but give you a lace card. (More efficient key combinations exist). A second alternative is punching the card via computer using the card reader/punch attached to the computer. Normally, this lets you punch characters on the card. But using the optional "punch column binary" instruction, you can punch an arbitrary 12-bit binary value in each column. So you can create a lace card this way, if it doesn't jam.
- vincent-manis 2y agoI remember that a lace card was a really good way of jamming an IBM 029 (or 026) card. You put the card in the feed hopper, and selected DUPlicate, it would almost always jam in the read station.