cvt 1024 768 60
# 1024x768 59.92 Hz (CVT 0.79M3) hsync: 47.82 kHz; pclk: 63.50 MHz
Modeline "1024x768_60.00"   63.50  1024 1072 1176 1328  768 771 775 798 -hsync +vsync
timea@timea-Aspire-5750G ~ $ sudo xrandr --newmode "1024x768_60.00"   63.50  1024 1072 1176 1328  768 771 775 798 -hsync +vsync
[sudo] password for timea:
timea@timea-Aspire-5750G ~ $ sudo xrandr -q
Screen 0: minimum 8 x 8, current 2390 x 768, maximum 32767 x 32767
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1366x768       60.0*+
   1360x768       59.8     60.0
   1280x720       60.0
   1024x768       60.0
   1024x576       60.0
   960x540        60.0
   800x600        60.3     56.2
   864x486        60.0
   640x480        59.9
   720x405        60.0
   680x384        60.0
   640x360        60.0
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
VGA-1-2 connected 1024x768+1366+0 0mm x 0mm
   1024x768       60.0*
   800x600        60.3     56.2
   848x480        60.0
   640x480        59.9
  1024x768_60.00 (0x120)   63.5MHz
        h: width  1024 start 1072 end 1176 total 1328 skew    0 clock   47.8KHz
        v: height  768 start  771 end  775 total  798           clock   59.9Hz
  1024x768 (0x43)   65.0MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x44)   40.0MHz
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  800x600 (0x45)   36.0MHz
        h: width   800 start  824 end  896 total 1024 skew    0 clock   35.2KHz
        v: height  600 start  601 end  603 total  625           clock   56.2Hz
timea@timea-Aspire-5750G ~ $ sudo xrandr --addmode VGA-1-2 1024x768_60.00