11 Feb
2023
11 Feb
'23
12:33 a.m.
Dan Cross wrote:
Oh yeah, I imagine [SUPDUP] was implemented on Lisp
machines, probably
for connecting to ITS. Lars, do you know?
I don't know if it was first implemented on ITS or Lisp machines, but
one of those two. SUPDUP is basically just ITS' internal terminal
buffer codes for text and cursor movement, adopted as a network
protocol. So certainly the first SUPDUP server would have been written
for ITS. Stanford's AI lab also adopted the protocol. But outside
those two sites, almost no one.
The name comes from "super-duper image mode", shortened to fit ITS' file
name limit of six characters. On ITS, a terminal may be opened in
"ASCII mode" which means control chacters are interpreted. In "image
mode" most control characters are passed through verbatim. There's a
special "super-image mode" where *all* characters are passed through.
So "super-duper image mode", then, alludes to the fact that even the
normally invisible internal codes are passed through.