~

The UNIX home directory equates to key '~' -- the above photo of Lear Siegler's ADM-3A computer terminal's full keyboard shows why.

It also shows why Bill Joy created VI with keys HJKL mapped to cursor position left/down/up/right:

0100 1000 H
0000 1000 BS (backspace; i.e., left)

0100 1010 J

0000 1010 LF (NL, line feed, new line; i.e., down)

0100 1011 K

0000 1011 VT (vertical tab; i.e., up)

0100 1100 L

0000 1100 FF (NP form feed; new page; i.e., right)

By selecting key 'Ctrl', the keyboard stripped the top bits, sending the HJKL key codes.

Note: per Wikipedia, "The Ctrl-H and Ctrl-J functions were standard, but the interpretations of Ctrl-K, Ctrl-L, and Ctrl-^ were unique to the ADM-3A." In other teletypes, VT means "down, a lot" and FF means "down, a page."

And why Mr. Joy chose key 'Esc' to switch modes--proximity.

The comments at Hacker News explain the other keys, such as why NUL equals ^@, why TAB equals ^I, why EOT equals ^D, and why ESC equals ^[ .

The Home key on the ADM-3A, incidentally, returned the cursor to the upper-left portion of the screen.