[tz] Tab/Space Formatting Inconsistency - Asia Ver 2023c

Paul Eggert eggert at cs.ucla.edu
Wed Dec 13 02:10:17 UTC 2023


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_Model_29_Card_Punch_Jun70.pdf



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