Value is `tty' for a tty console (a character-only terminal),
`x' for a console that is an X display,
`mswindows' for a console that is a Windows NT/95/97 connection,
Value is `tty' for a tty console (a character-only terminal),
`x' for a console that is an X display,
`mswindows' for a console that is a Windows NT/95/97 connection,