Mach64 X Server Release Notes : XF86Config options
Previous: Optimizing the speed of the Mach64 X server
Next: Enhancements for this release

## 3. XF86Config options

Several options are supported in the "Device" section for the Mach64 X server. By default, the Mach64 X server will determine the RAMDAC type from the BIOS. If you wish to override the default RAMDAC type (not recommended unless the BIOS incorrectly reports your RAMDAC type), you can specify the RAMDAC type in the XF86Config file with the "Ramdac" entry. The Mach64 X server will also program the clocks based on the clock chip read from the BIOS. If you wish to override the default clock chip type (not recommended unless the BIOS incorrectly reports your clock chip type), you may specify the clock chip in the XF86Config file with the "ClockChip" entry. If, however, you wish to use the preprogrammed clocks, you can turn off the clock programming with the "no_program_clocks" option. In this case, the Mach64 X server reads the Clocks from the BIOS. The "Clocks" lines in the XF86Config file are normally ignored by the Mach64 X server unless the "no_bios_clocks" option is given. Note on newer Mach64 cards (CT, ET, VT, GT, 3D Rage II, 3D Rage II+DVD and Rage Pro) the "Ramdac", "ClockChip" and "Clocks" lines have no meaning and should not be included in your XF86Config file.

Option "sw_cursor"

  This option allows you to use the software cursor instead of the hardware cursor.

Option "hw_cursor"

  This option turns on the hardware cursor. This should not be necessary since the hardware cursor is used by default unless the "sw_cursor" option is specified.

Option "composite"

  This option will set the composite sync for monitors that require this.

Option "dac_8_bit"

  This option enables 8 bits per RGB value. Note that this does not work with the Chrontel 8398 RAMDAC. This options is not necessary since 8 bits per RGB value is the default for the Mach64 X server for all Mach64 cards except those with the Chrontel 8398 RAMDAC.

Option "dac_6_bit"

  This option enables 6 bits per RGB value.

Option "override_bios"

  This option allows you to specify a video mode that the video card's BIOS believes to be illegal. Some BIOSs have incorrect maximum resolution and/or dot clock limitations. Use this option with extreme care. It is possible to specify a video mode that can damage your card or monitor.

Option "no_block_write"

  This option allows you to turn off block write mode. Block write mode only works on certain types of VRAM cards. This option has no effect on DRAM based cards. If you see noise on the screen that can be captured via xmag, then it is probably a problem with block write mode being turned on when it should not. This ``noise'' usually looks like bits of windows/menus repeated on the screen.

Option "block_write"

  This option allows you to turn on block write mode. Block write mode only works on certain types of VRAM cards, and this option has no effect on DRAM based cards. If you want to override the probed default, you can use this option. Note that this may result in ``noise'' appearing on the screen.

Option "power_saver"

  This option allows the server to use the power saving features of certain "green" monitors instead of blanking when the screen saver is activated. This option is still experimental.

Option "no_program_clocks"

  This option allows you to disable the clock programming. Normally the Mach64 server will program the clocks based on the clock chip type unless this option is given. With this option, the clocks are either read from the BIOS or, if the "no_bios_clocks" option is set, set from the Clocks line.

Option "no_bios_clocks"

  This option allows you to override the clocks read from the video card's BIOS and use the clocks specified in the Clocks line in your XF86Config file. Normally the Mach64 server will ignore both the BIOS clocks and the clocks specified in the Clocks line unless the "no_program_clocks" options is set (see above).

Option "no_font_cache"

  This option allows you to disable the font cache. By default the font cache is turned on if the horizontal resolution is 1024 pixels or greater and there is enough off-screen video memory to hold the cache.

Option "no_pixmap_cache"

  This option allows you to disable the pixmap cache. By default the pixmap cache is turned on if the horizontal resolution is 1024 pixels or greater and there is enough off-screen video memory to hold the cache.

MemBase baseaddress

  This entry specifies the video memory aperture address. By default the aperture address is automatically determined and this option should not be necessary. If the Mach64 X server is dying with a seg. fault, then the memory aperture might not be correctly determined. To fix this try setting the aperture address to another location.

ClockChip "type"

  This entry specifies the clock chip type. The following values are valid for type:

  - ati18818
  - att20c408
  - ch8398
  - ibm_rgb514
  - ics2595
  - stg1703
Ramdac "type"

  This entry specifies the RAMDAC type. The following values are valid for type:

  - ati68860
  - ati68860b
  - ati68860c
  - ati68875
  - att20c408
  - ch8398
  - ibm_rgb514
  - internal
  - stg1702
  - stg1703
  - tlc34075
DacSpeed "MHz"

  This entry allows you to override the default maximum dot clock. Use this option with extreme caution. If you specify a MHz value too large for your card, you can damage it.

Mach64 X Server Release Notes : XF86Config options
Previous: Optimizing the speed of the Mach64 X server
Next: Enhancements for this release