[rgoulter]

> I suppose you're saying ASCII 10 was chosen as newly because it aligns with the down arrow on keyboards of the time. Maybe.

The linked StackExchange has it as:

> What character was used for what control code was mostly a matter of bitwise arithmetics. LF is ^J because J happens to be at the corresponding location in the corresponding column of the table (+ 64 in decimal)

[microgpt]

and did they choose that code because the J key had a down arrow printed on it?

[ahazred8ta]

No, the Baudot / Western Union mechanical teletype code assignments were worked out in the late 1800s and early 1900s. This was later developed into ASCII. Computer keyboards came much later. https://en.wikipedia.org/wiki/Baudot_code