1234123456789123456789 ESC[0$- No stausline
ESC[1$- Indicator statusline
ESC[2$- Hostwritable statusline
ESC[0$} Enter main display
ESC[1$} Enter statusline
If the statusline is not set to ``hostwritable'', entering the statusline will cause no text to be displayed.
Nearly all commands of the text terminal emulation work in the status- line, changing attributes, modes and character sets effect the main display too (like they do on a real VT3XX).
Commands that do not work:
save and restore cursor,
test pattern,
all DEC private mode set and reset commands,
set scrolling region.