Tente xrandr. Existe o meu script rotativo para o EeePC com monitor externo
#!/bin/bash
# usage:
# ./rotate VGA1 right
s=${1:-'LVDS1'}
r=${2:-'left'}
echo $s;
# see 'xrandr' for output modes for all screens
case $s in
'LVDS1')
m='1024x600' #default resolution of EeePC 1005ha
;;
'VGA1')
m='1024x768' #best resolution for LG FLATRON 795FT Plus which plugged to EeePC
;;
esac
case 'xrandr | grep $s | sed 's/^\(.*\+0 \)\(.*\) (.*//g'' in
'left')
echo 'returning from left to the normal state on screen '$s' with the '$m' mode'
xrandr --output $s --mode $m --rotate normal
;;
'right')
echo 'returning from right to the normal state on screen '$s' with the '$m' mode'
xrandr --output $s --mode $m --rotate normal
;;
*)
echo 'rotating to the '$r' on screen '$s' with the '$m' mode'
xrandr --output $s --mode $m --rotate $r
;;
esac