[grymoire1]

This is why the DEL key is all ones. It was used to overpunch the wrong letter on a paper tape and replace it with a character that meant ignore (delete) it.

As done on an ASR-33 https://en.wikipedia.org/wiki/Teletype_Model_33

[muterad_murilax]

I'm sorry, "all ones"?

[ufo]

The ASCII code for DEL is 127, which is 1111111 in binary.

[muterad_murilax]

Ah, of course. :) Thanks for the clarification!

[alblue]

Yup, I talked about this (and the origins of ASCII and why Ctrl+M is new line etc) in a talk I gave at the end of last year entitled "A brief history of Unicode". The video recording has just been published on InfoQ:

https://www.infoq.com/presentations/unicode-history

[mdrzn]

Really interesting! Thanks for sharing.