>>>Also, in Hollerith code the letters J-R use the 11 punch.
>
>Had to look that up, as it predates what I had believed to be elder computer memories. I caught the very end of the card punch era when the Uni Computer Society purchased a mainframe for all cash on hand = $26 and a six-pack of beer. So charmed were the industrial sellers to declare this the winning bid, that they spent a fortune delivering it to the Human Sciences building that was being fitted out at the time, creating a downstream furor when it was discovered that it couldn't be gotten out again without dismantling interior walls. Those were the days. This one had the latest multi-platter Winchester drive that sounded like a flying saucer when it spooled up before activating the circuit breakers, plunging lecture theaters into darkness. Yes, my enjoyment of chaos certainly was well-served by that wonderful machine. ;-)

I came of age technically while punch cards and paper tape were the only ways of communicating with computers.

It still amazes me to think that the entire US Social Security system ran on punched cards for quite a while before magnetic tape came along.

One of the most brilliant innovations I ever saw came during the early 60's from an engineer at IBM who had the insight that rounded corners on punched cards (they had been square up to that point) would not reduce data capacity, but would save millions of tons of paper per year and reduce jams on card handling machines.

A complete win in every respect.

Millions of engineers around the world looked on with envy- "Why didn't I think of that?"