grub vga modes

Here's a table of the grub vga modes you can use in your /boot/grub/grub.conf or menu.lst.

Color   | 640x480  800x600  1024x768 1280x1024


--------+-------------------------------------


 8bit   |   769      771       773      775


15bit   |   784      787       790      793


16bit   |   785      788       791      794


24bit   |   786      789       792      795

Debian/Ubuntu:
/boot/grub/menu.lst

RedHat/Fedora/CentOS
/boot/grub/grub.conf

Your kernel line may look like this:

kernel  /boot/vmlinuz-2.6.24-21-generic root=UUID=d82ba1ab-f84f-4354-b118-543a2804a26b ro quiet splash

On most systems you can just change the last splash (and quiet) to vga=791 or something from the table like:

kernel  /boot/vmlinuz-2.6.24-21-generic root=UUID=d82ba1ab-f84f-4354-b118-543a2804a26b ro vga=791

(The "quiet" gives less output on the screen while booting and "splash" loads a distribution specific graphic, sometimes animated but mostly boring)

If you get a blank screen while booting it may be because you don't have a working framebuffer.
I would search for the keywords framebuffer, linux, radeon, hp. But that's me and my computer.