On 12/12/23 17:46, Paul Gilmartin via tz wrote:
On IBM 80 column punch cards, the tab, 0x05 (rarely used), occupies only a single column, regardless of its appearance on output devices.
0x05 was rarely used because columns were aligned without using tab characters. The IBM 029 card punch[1] had a program drum, which let the operator set the equivalent of tab stops at whatever columns were needed. Tab stops didn't need to be every 8 columns, and didn't even need to be at regular intervals. Pressing the SKIP key would cause the card punch to skip ahead to the next tab stop, at a marvelous rate of 80 columns per second. The resulting data therefore did not contain tab characters and did not record where the tab stops were. We could get a similar effect by expanding all tabs to spaces in the TZDB source code. Some projects do that - partly to avoid distractions like this email thread! [1]: https://www.masswerk.at/keypunch/manuals/IBM029-GA24-3332-6_Reference_Manual...