[TUHS] Word erase?

[Dan Cross <crossd@gmail.com>]

I wonder if anyone can shed any light on the timing and rationale for
the introduction of “word erase” functionality to the kernel terminal
driver. My surface skim earlier leads me to believe it came to Unix
with 4BSD, but it was not reincorporated into 8th Edition or later,
nor did it make it to Plan 9 (which did incorporate ^U for the "line
kill" command).  TOPS-20 supports it via the familiar ^W, but I'm not
sure about other PDP-10 OSes (Lars?).  Multics does not support it.
VMS does not support it.

What was the proximal inspiration?  The early terminal drivers seem to
use the Multics command editing suite (`#` for erase/backspace, `@`
for line kill), though at some point that changed, one presumes as
TTYs fell out of favor and display terminals came to the fore.

        - Dan C.