9 Apr
2002
9 Apr
'02
7:40 p.m.
From: Carlini, Antonio <Antonio.Carlini(a)riverstonenet.com>
My quick check of the the VT102 and VT220 manuals
does not show "ESC /" as a recognised emulated
VT52 sequence. The VT100 manual makes it quite
clear how to react to random ESCape sequences.
It is pretty silent on VT52 emulation mode. I suspect
the VSRM is too (if we still have one in
the office, I'll check tomorrow).
Vt100 and later were ANSI extended terminals. VT52 however
was pre ansi. The behavour for unknown escapes in vt52 were
generally no-ops or redundant decodes. The closest VT52
emulation for 80 char modes was H19 (it could not do the
132 wide and doublewidth).
When I wrote a VT102 emulator, many moons
ago, I know that since most VT52 escape
sequences were of the form "ESC x" then
I would have ignored "ESC x" for an
unrecognised "x" and displayed
"ABC" when fed "A ESC / BC". It seems
that real VT terminals do not do this.
VT52 was very different from VT100 and later.
many of the VT52 sequences were both
constrained by 7bit ascii and it's very limited intelligence.
The only way to determine whether the VT1xx
is a faithful VT52 emulator is to see what
a real VT52 does. (Or read the schematics,
which I believe are online).
True, though a real VT100 in VT52 mode is safe.
Allison