[Chinasol]

It's great to see the old 80-column punched card standard fossilised in these modern environments...

[wpietri]

And my understanding is that we got punched cards of that size because they fit into the boxes and drawers for large-format US banknotes:

http://en.wikipedia.org/wiki/Large-sized_note

Which in turn apparently goes back to taking a common paper size and cutting it into reasonably-sized pieces:

http://ask.metafilter.com/262846/What-is-the-origin-of-the-d...

So apparently one person lost to history said, "How big should it be? I don't know. Maybe about this big?" Centuries later, somebody at IBM said, "It looks like we could fit 80 columns on that. Good enough?"

[kps]

Hollerith cards originally had 45 columns.

[kps]

Line length around 80 columns come from letter paper in a typewriter (via teleprinters) which in turn comes from book printing, where around 60–65 printed characters (plus blanks) were established as most readable centuries ago.

[XorNot]

80 columns gives you 3 files side-by-side on a 1920 monitor.

[skj]

Surely that depends on more than just the number of columns and the number of pixels.