Setting the screen resolution on Darwin/x86

Rob Braun

Darwin Developer
Revision History
Revision 116 April 2001rb - [email protected]


Changing your screen resolution with Darwin/x86 is an important, but non-obvious task. This document will try to describe how it is done. The specifics can be found in boot/i386/boot2/graphics.c.

Table of Contents

The Default.table File

The Default.table File

The display resolutions for Darwin/x86 are set at boot time in the file /private/Drivers/i386/System.config/{Default,Instance0}.table. The tag for setting the resolution is "Graphics Mode". Here's the mapping of known tags to the resolution/bit depth. The format is in the form of resolution (XxY) and a tag representing the color. For lower bit depths, this is pretty obvious, but the higher ones are non-obvious.

Tag              Meaning
"640x400x256"    640 by 400 at 8bpp
"640x480x256"    640 by 480 at 8bpp 
"800x600x16"     800 by 600 at 4bpp 
"800x600x256"    800 by 600 at 8bpp 
"1024x768x16"    1024 by 768 at 4bpp 
"1024x768x256"   1024 by 768 at 8bpp 
"1280x1024x16"   1280 by 1024 at 4 bpp 
"1280x1024x256"  1280 by 1024 at 8bpp 
"640x480x555"    640 by 480 at 24 bpp 
"640x480x888"    640 by 480 at 32 bpp 
"800x600x555"    800 by 600 at 24 bpp 
"800x600x888"    800 by 600 at 32 bpp 
"1024x768x555"   1024 by 768 at 24 bpp 
"1024x768x888"   1024 by 768 at 32 bpp 
"1280x1024x555"  1280 by 1024 at 24 bpp 
"1280x1024x888"  1280 by 1024 at 32 bpp