Gregory's ServerWelcome to Having a Normal One, I'm your host and today we're reading the ANSI specification for rectangular holes in standard IBM punched cards.
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With gratitude to the Internet Archive (@internetarchive), for digitizing and publishing this important piece of history. And incidentally saving me money, because the standard may be utterly historical and irrelevant, but that won't stop ANSI from charging $60 for the PDF. Never let common sense get in the way of revenue, I guess. I sent $60 to the Internet Archive instead, since that's apparently the going rate for knowing how to punch some cards. I encourage you to donate also! @danderson @internetarchive And go visit their SF building if you're in the vicinity on a Friday afternoon because it's *awesome* :D |
Not much of a read if I'm honest, once you get past the foreword, the list of agencies that signed off, the list of contributors and the index, it fits on a single two-sided sheet of paper: the punch holes must be 0.125" by 0.055", ±0.001".
The centers of the holes are laid out on a grid. Twelve lines 0.250" apart on the short axis, N lines spaced 0.087" on the long axis. Each intersection is the center point of a hole. ±0.010" center position error allowed when punching, ±0.018" when reading.