Résolutions d’écran VGA

Source :

http://www.pendrivelinux.com/vga-boot-modes-to-set-screen-resolution/

http://pierre.baudu.in/other/grub.vga.modes.html

GRUB VGA Modes

GRUB allows you to choose the VGA definition it uses when booting.
(Note: this does not affect the definition in Xorg).

You need to add the option vga=xxx on the kernel stanza in the file /boot/grub/menu.lst.

Of course, replace xxx with the video mode you want. Your kernel stanza will look like this :

 kernel /boot/vmlinuz-2.6.18-6-686 root=/dev/sda7 ro vga=791

Here is a list of the available video modes:

Colour depth	640×480	800×600	1024×768	1280×1024	1400×1050	1600×1200
8 (256)	769	771	773	775
15 (32K)	784	787	790	793
16 (65K)	785	788	791	794	834	884
24 (16M)	786	789	792	795