tset vt100 destroys scrolling on SUN-2/120
g...@ucbvax.berkeley.edu
> >We have discovered that accidentally doing a "tset vt100" from
> >our SUN consoles screws up their scrolling (and vi, and more, and....)
> >The problem is due to the initialization string sent to the
> >console (ESC[1;24r)....
>
> In the list of commands that the SUN terminal emulator groks is a note
> that the sequence <ESC[s> will reset the terminal to a sort of virgin
> state. Especially useful is that it undoes the set-scrolling-area
> limit of 24 lines that your vt-100 tset did.
The SUN console/terminal emulator don't interpret <ESC>[N;Mr as a
VT100-style "set scrolling region" command - that escape sequence is in the
series reserved by X3.64 for private escape sequences, and "set scrolling
region" is DEC-private. The escape sequences are documented in the Sun UNIX
2.0 manual page CONS(4S), where it also says
The Sun terminal emulator and the VT100 are *not* compatible
in any true sense. (Italics in the original).
<ESC>[Nr is "set scrolling" (SUNSCRL), which takes one parameter, default 0.
It "sets to N an internal register which determines how many lines the
screen scrolls up when a line-feed function is performed with the cursor on
the bottom line". An N of 1 is the normal mode; N of the screen size causes
the screen to clear instead of scrolling; N of some small value >1 causes
the screen to jump a bit when scrolling. N of 0 causes the console, but not
the SunWindows terminal emulator, to move the cursor to the top line without
scrolling; the top line is cleared, but the screen is otherwise unchanged.
Guy Harris