915resolution

A tool to modify the video BIOS of 800 and 900 series Intel graphics chipsets

Notes

915resolution supports the 845G, 855GM, 865G, 915G, 915GM, 945G, and 945GM chipsets.

915resolution must run before the X server is started.

915resolution only patches the RAM of the video BIOS, so the new resolution is lost at each reboot. To automate the modification process, please consult your distribution's documentation.

915resolution requires root privileges.

Usage

Usage: 915resolution [-l] [mode X Y] [bits/pixel] Options: -l display the modes found in the video BIOS

Note that bits per pixel is optional. If nothing is specified, then the original value will be preserved.

Installation

$ make $ su

make install

Example

1. Display the available resolutions :

    # 915resolution -l
    Intel 800/900 Series VBIOS Hack : version 0.5.3

    Chipset: 915GM
    BIOS: TYPE 1
    Mode Table Offset: $C0000 + $269
    Mode Table Entries: 36
    Mode Table Offset: $C0000 + $269
    Mode Table Entries: 36

    Mode 30 : 640x480, 8 bits/pixel
    Mode 32 : 800x600, 8 bits/pixel
    Mode 34 : 1024x768, 8 bits/pixel
    Mode 38 : 1280x1024, 8 bits/pixel
    Mode 3a : 1600x1200, 8 bits/pixel
    Mode 3c : 1920x1440, 8 bits/pixel
    Mode 41 : 640x480, 16 bits/pixel
    Mode 43 : 800x600, 16 bits/pixel
    Mode 45 : 1024x768, 16 bits/pixel
    Mode 49 : 1280x1024, 16 bits/pixel
    Mode 4b : 1600x1200, 16 bits/pixel
    Mode 4d : 1920x1440, 16 bits/pixel
    Mode 50 : 640x480, 32 bits/pixel
    Mode 52 : 800x600, 32 bits/pixel
    Mode 54 : 1024x768, 32 bits/pixel
    Mode 58 : 1280x1024, 32 bits/pixel
    Mode 5a : 1600x1200, 32 bits/pixel
    Mode 5c : 1920x1440, 32 bits/pixel
    Mode 60 : 1280x770, 8 bits/pixel
    Mode 61 : 1280x770, 16 bits/pixel
    Mode 62 : 1280x770, 32 bits/pixel
    Mode 63 : 512x771, 8 bits/pixel
    Mode 64 : 512x771, 16 bits/pixel
    Mode 65 : 512x771, 32 bits/pixel

2. Consider the example of overwriting Mode 38 :

    # 915resolution 38 1280 800

3. Now the BIOS reports a 1280x800 resolution :

    # 915resolution -l
    Intel 800/900 Series VBIOS Hack : version 0.5.2

    Chipset: 915GM
    BIOS: TYPE 1
    Mode Table Offset: $C0000 + $269
    Mode Table Entries: 36
    Mode Table Offset: $C0000 + $269
    Mode Table Entries: 36

    Mode 30 : 640x480, 8 bits/pixel
    Mode 32 : 800x600, 8 bits/pixel
    Mode 34 : 1024x768, 8 bits/pixel
    Mode 38 : 1280x800, 8 bits/pixel
    Mode 3a : 1600x1200, 8 bits/pixel
    Mode 3c : 1920x1440, 8 bits/pixel
    Mode 41 : 640x480, 16 bits/pixel
    Mode 43 : 800x600, 16 bits/pixel
    Mode 45 : 1024x768, 16 bits/pixel
    Mode 49 : 1280x800, 16 bits/pixel
    Mode 4b : 1600x1200, 16 bits/pixel
    Mode 4d : 1920x1440, 16 bits/pixel
    Mode 50 : 640x480, 32 bits/pixel
    Mode 52 : 800x600, 32 bits/pixel
    Mode 54 : 1024x768, 32 bits/pixel
    Mode 58 : 1280x800, 32 bits/pixel
    Mode 5a : 1600x1200, 32 bits/pixel
    Mode 5c : 1920x1440, 32 bits/pixel
    Mode 60 : 1280x770, 8 bits/pixel
    Mode 61 : 1280x770, 16 bits/pixel
    Mode 62 : 1280x770, 32 bits/pixel
    Mode 63 : 512x771, 8 bits/pixel
    Mode 64 : 512x771, 16 bits/pixel
    Mode 65 : 512x771, 32 bits/pixel

4.  On some machines 24 bits per pixel is desired.
    An invocation to achieve this is:

    # 915resolution 38 1280 800 24

6. Start the X server
    # startx

Chipset information

CHIPSET	ID	PAM
845G, 845GL, 845GV	$2560_8086	$91 - $92
865G, 865GV	$2570_8086	$91 - $92
855GM, 855GME, 852GM, 852GMV	$3580_8086	$5A - $5b
915G	$2580_8086	$91 - $92
915PM, 915GM, 915GMS, 910GML	$2590_8086	$91 - $92
945G	$2770_8086	$91 - $92
945GM	$27A0_8086	$91 - $92

Provenance disclaimer

This program incorporated public domain work originally written by Steve Tomljenovic, which was itself based on techniques in the work of Christian Zietz, Andrew Tipton, and Alain Poirier.

More thorough information can be found on Steve Tomljenovic's website, which is archived here.

pngdeity / 915resolution