XF86_Accel(1)

NAME
XF86_Accel - 8 bit accelerated X Window System servers for UNIX on x86 platforms with an S3, Mach8, Mach32 or 8514/A accelerator board

SYNOPSIS
XF86_S3 [:displaynumber] [ option ] ...

XF86_Mach8 [:displaynumber] [ option ] ...

XF86_Mach32 [:displaynumber] [ option ] ...

XF86_8514 [:displaynumber] [ option ] ...

DESCRIPTION
XFree86 is a package of bug-fixes, enhancements, and ports of X11R5 to new OSs, for Intel Unix-like OSs. See the XFree86(1) manpage for details.

XF86_S3 is an 8-bit PseudoColor server for S3 graphic accelerator boards.

XF86_Mach8 is an 8-bit PseudoColor server for ATI Mach8 graphic accelerator boards.

XF86_Mach32 is an 8-bit PseudoColor server for ATI Mach32 graphic accelerator boards.

XF86_8514 is an 8-bit PseudoColor server for 8514/A graphic accelerator boards.

These are derived from the X386 server provided with X11R5, and from the X8514 server developed by Kevin Martin <martin@cs.unc.edu>.

The XFree86 servers support all MIT-supplied extensions except the X Input Extension. PEX is supported, but does not function well on the class of hardware supported.

CONFIGURATIONS

The servers support the following chipsets in 256 color mode.

    XF86_S3:
        86C911, 86C924, 86C801, 86C805, 86C928

    XF86_Mach8:
        ATI Mach8, ATI Mach32

    XF86_Mach32:
        ATI Mach32

    XF86_8514:
        IBM 8514/A and true clones

For S3 virtual resolutions up to (approximately) 1152x800 are supported, using (up to) 1Mb of display memory (the S3 uses an internal width of 1280 except for new revisions of some of the chips, hence 1Mb can't support 1152x900). Physical resolutions up to 1280x1024 (1600x1280 on some cards) are possible using 2Mb or more of display memory (virtual resolution is dependent solely on the amount of memory installed, with the maximum virtual width being 2048, and max virtual height is 4096). Similar resolutions are supported on the Mach32. For the Mach32, the maximum virtual width is 1536, and the maximum virtual height is 1280. For Mach8, the maximum virtual width is 1024, and for 8514 the maximum resolution is 1024x768.

OPTIONS
In addition to the normal server options described in the Xserver(1) manual page, these servers accept some more command line switches, as described in the XFree86(1) manpage.

KEYBOARD
XFree86 provides several capabilities for easing the use of international keyboards, and generating non-ASCII Latin-1 keysyms. Refer to the XFree86kbd(1) manual page for more information.

SETUP
XFree86 uses a configuration file called Xconfig for its initial setup. See the Xconfig(4/5) manpage for general details. Here only the parts specific to the XF86_S3, XF86_Mach8, XF86_Mach32, XF86_8514 servers are explained. The GRAPHICS DRIVER SETUP section for the accelerated colour servers starts with the keyword accel. After this keyword a variety of options may be specified:

chipset "name"
    specifies a chipset so the correct driver can be used. Possible chipsets are:

    XF86_S3:

    s3_generic
        (for a standard IO driven server)

    mmio_928
        (for a memory mapped IO driven server on 86C928 boards)

    XF86_Mach8:

    mach8
        (to force the Mach8 server to run on Mach32 boards)

    XF86_Mach32:

    mach32

    XF86_8514:

    ibm8514

clocks clock ...
    specifies the dotclocks that are on your graphics board. The clocks are in MHz, and may be specified as a floating point number. The value is stored internally to the nearest kHz. The ordering of the clocks is important. It must match the order in which they are selected on the graphics board. Multiple clocks lines may be specified. For programmable clock chips the name of the clockchip is given. Possible values include "icd2061a" and "sc11412". These are currently only supported by the S3 server.

membase memaddress
    specifies the hard-wired part of the linear framebuffer base address. This option is only used by the S3 and Mach32 servers (and only when using a linear framebuffer). For the S3 server, the hard-wired part is the high 6 bits of the 32-bit address (ie memaddress is masked with 0xFC000000). For the Mach32 server, the mask is 0xF8000000 (except for PCI cards, where the membase setting is ignored).

    Note: The S3 server will normally probe for this address automatically. Setting this option overrides that probe. This is not normally recommended because the failure of the server's probe usually indicates problems in using the linear framebuffer.

option "optionstring"
    allows the user to select certain options provided by the drivers. Currently the following strings are recognized:

    nomemaccess - (S3) disable direct access to video memory.

    nolinear - (S3 and Mach32) disable use of a linear-mapped framebuffer.

    normal_dac - (S3) Card does not have one of the other RAMDACs mentioned here. This option is only required if the server incorrectly detects one of those other RAMDACs.

    att_20c490_1 - (S3) Card has an AT&T 20C490 or AT&T 20C491 RAMDAC. This option when combined with the dac_8_bit option allows these RAMDACs to be operated in 8 bit per RGB mode. There is currently no auto-detection for these RAMDACs. Note that 8 bit per RGB mode does not appear to work with the Winbond 82C490 RAMDACs (which SuperProbe identifies as AT&T 20C492).

    sc15025 - (S3) Card has a Sierra SC15025 or SC15026 RAMDAC. This option when combined with the dac_8_bit option allows these RAMDACs to be operated in 8 bit per RGB mode. There is currently no auto-detection for these RAMDACs.

    bt485 - (S3) Card has a BrookTree Bt485 RAMDAC. This option is required if the server fails to detect the Bt485.

    20c505 - (S3) Card has an AT&T 20C505 RAMDAC. This option is required either if the server fails to detect the 20C505, or if the card has a Bt485 RAMDAC and there are problems using clocks higher than 67.5Mhz.

    bt485_curs - (S3) Enables the Bt485's internal HW cursor. This option may be used for cards with Bt485 or AT&T 20C505 RAMDACs.

    ti3020 - (S3) Card has a TI ViewPoint Ti3020 135MHz RAMDAC. This option is required if the server fails to detect the Ti3020. This is the default if a Ti3020 RAMDAC is detected and the ti3020_fast option is not set. Note that pixel multiplexing will be used for this RAMDAC if any mode requires a dot clock higher than 70MHz. Pixel multiplexing with this RAMDAC does not support physical mode widths less than 1024 or interlaced modes. Also, the only logical line widths that work when operating in pixel multiplex mode are 1024 and 2048.

    ti3020_fast - (S3) Card has a TI ViewPoint Ti3020 200MHz RAMDAC.

    ti3020_curs - (S3) Enables the Ti3020's internal HW cursor. (Default)

    no_ti3020_curs - (S3) Disables the Ti3020's internal HW cursor.

    sw_cursor - (Mach32) Disable the hardware cursor.

    dac_8_bit - (S3, Mach32) Enables 8-bit per RGB. Currently only supported with the Ti3020, AT&T 20C490/1, Sierra SC15025/6 (S3 server) and ATI68875/TLC34075/Bt885 (Mach32 server) RAMDACs.

    intel_gx - (Mach32) Sets the hard-wired offset for the linear framebuffer correctly for the Intel GX Pro cards. This option is equivalent to setting the membase to 0x78000000.

    spea_mercury - (S3) Enables pixel multiplex support for SPEA Mercury cards (928 + Bt485 RAMDAC). For these cards, pixel multiplexing is required in order to use dot clocks higher than 67.5 MHz and to access more than 1MB of video memory. Pixel multiplexing is currently supported only for non-interlaced modes, and modes with a physical width no smaller than 1024.

Note that XFree86 has some internal capabilities to determine what hardware it is running on. Thus normally the keywords chipset, clocks, and videoram don't have to be specified. But there may be occasions when this autodetection mechanism fails, (for example, too high of load on the machine when you start the server). For cases like this, one should first run the server on an unloaded machine, look at the results of the autodetection (that are printed out during server startup) and then explicitly specify these parameters in the configuration file. It is recommended that all parameters, especially Clock values, be specified in the Xconfig file.

The last section is the TABLE OF VIDEO MODES which starts with the keyword modedb. This is covered in the Xconfig(4/5) manpage. For details on how to build your own video modes please refer to the tutorial written by Eric Raymond.

FILES

/usr/X386/bin/XF86_S3
    The 8-bit color X server for S3

/usr/X386/bin/XF86_Mach8
    The 8-bit color X server for Mach8

/usr/X386/bin/XF86_Mach32
    The 8-bit color X server for Mach32

/usr/X386/bin/XF86_8514
    The 8-bit color X server for IBM 8514 and true compatibles

/usr/X386/lib/X11/Xconfig
    Server configuration file

SEE ALSO
X(1), Xserver(1), XFree86kbd(1), XFree86(1), Xconfig(4/5), xdm(1), xinit(1)

AUTHORS

In addition to the authors of XFree86 the following people contributed major work to this server:

Kevin Martin,    martin@cs.unc.edu
Jon Tombs,       jon@gtex02.us.es
Rik Faith,       faith@cs.unc.edu
    Did the overall work on the base accelerated servers.

David Dawes,     dawes@physics.su.oz.au
Dirk Hohndel,    hohndel@informatik.uni-wuerzburg.de
David Wexelblat, dwex@goblin.org, dwex@aib.com
    Merged their work into XFree86.

Jon Tombs,       jon@gtex02.us.es
David Wexelblat, dwex@goblin.org, dwex@aib.com
David Dawes,     dawes@physics.su.oz.au
Amancio Hasty,   hasty@netcom.com
Robin Cutshaw,   robin@paros.com
    Development and improvement of the S3 specific code.

Kevin Martin,    martin@cs.unc.edu
Rik Faith,       faith@cs.unc.edu
Tiago Gons,      tiago@comosjn.hobby.nl
Hans Nasten,     nasten@everyware.se
Scott Laird,     lair@midway.uchicago.edu
    Development and improvement of the Mach8 and 8514/A specific code.

Kevin Martin,    martin@cs.unc.edu
Rik Faith,       faith@cs.unc.edu
Mike Bernson,    mike@mbsun.mlb.org
Mark Weaver,     Mark_Weaver@brown.edu
Craig Groeschel, craig@adikia.sccsi.com
    Development and improvement of the Mach32 specific code.

See also the XFree86(1) manual page.

BUGS

S3 cards with Bt485 ramdacs are currently restricted to dot-clocks less than 85MHz. This restriction is because the servers don't yet support operating the ramdacs in multiplexed mode.

CONTACT INFO
XFree86 source is available from the FTP servers ftp.physics.su.oz.au and ftp.x.org. Send email to XFree86@physics.su.oz.au for details.