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svgalib.mach32(7)             Svgalib User Manual            svgalib.mach32(7)

       svgalib.mach32 - Information on the Mach32 chipset driver

        0. Introduction
        1. Specifying pixel clocks
        2. Copyrights
        3. The mach32info utility
        4. Third party cards
        5. Logical line width
        6. Noisy video signals
        7. The configuration EEPROM
        8. EEPROM woes
        9. The Mach32Eeprom command
       10. Setup of the memory aperture (linear framebuffer)
       11. Accelerator support and other weird features
       12. Ramdacs
       13. Meaning of the detection message from svgalib
       14. Conclusions

       The  driver  should allow you to use any of the graph-modes your Mach32
       card supports. Note that there is no support for <8bpp modes and that I
       won't  ever implement that because I don't see any reason for doing so.
       All standard VGA-modes are supported, of course (by using the  standard
       VGA driver routines).

       If  you configured your Mach32 for a memory aperture and it is at least
       as big as the memory of your card (that is, not a 1MB  memory  aperture
       for  a  2MB  card) support for linear frame buffer access of svgalib is

       Auto detection of the Mach32 seems not to work  on  all  cards.  That's
       really  strange since I got the code from the X people. It should be OK
       regardless of my docs. Well, I fixed that (hopefully). Actually the bug
       was  found  by Daniel Lee Jackson (djacksonATichips.com).  (Thanks
       again.. It was so silly... I would have never found it)  If  you  still
       have problems just put a chipset Mach32 in your config file.

       WARNING!  The Mach32 driver needs to know correct clock frequencies for
       graceful DAC configuration. Wrong clocks may damage your card! However,
       this  version  contains code for automatic clock detection. Since clock
       detection is time critical, please do it on a completely  idle  system.
       Then put the printed out clocks line in your libvga.config(5) file.

       The driver tries to do this for you.  After that, you can restart what-
       ever svgalib program you used and you are set. If  you  already  put  a
       clocks  line  in your config by hand, comment it out to have the driver
       check your clocks.

       Since clock probing is time critical, values differ from time to  time,
       you  may  try  it  multiple  times and see which values seem to be most
       exact. You can also compare them with  the  standard  clock  chips  for
       Mach32 cards in libvga.config(5)).

       The clock probing relies on the 7th clock being 44.9MHz as this is what
       Xfree does.  If this is not true (and it is  not  always),  probing  is
       hosed.  See  libvga.config(5)  for  a list of the clocks used by common
       svgalib cards.

       Some tiny routines are copied from Xfree86. The clock detection code is
       almost  just  copied.  So  I  repeat the copyright statements for these
       parts here:

       Copyright 1992 by Orest Zborowski <obzATKodak.com>
       Copyright 1993 by David Wexelblat <dwexATgoblin.org>

       Permission to use, copy, modify, distribute, and sell this software and
       its  documentation  for any purpose is hereby granted without fee, pro-
       vided that the above copyright notice appear in  all  copies  and  that
       both  that  copyright  notice and this permission notice appear in sup-
       porting documentation, and that the names of Orest Zborowski and  David
       Wexelblat not be used in advertising or publicity pertaining to distri-
       bution of the software  without  specific,  written  prior  permission.
       Orest  Zborowski  and David Wexelblat make no representations about the
       suitability of this software for any purpose. It is  provided  "as  is"
       without express or implied warranty.

       Orest Zborowski and David Wexelblat disclaim all warranties with regard
       to this software, including all implied warranties  of  merchantability
       and  fitness,  in  no event shall Orest Zborowski or David Wexelblat be
       liable for any special, indirect or consequential damages or  any  dam-
       ages whatsoever resulting from loss of use, data or profits, whether in
       an action of contract, negligence or other tortious action, arising out
       of or in connection with the use or performance of this software.

       Copyright 1990,91 by Thomas Roell, Dinkelscherben, Germany.
       Copyright 1993 by Kevin E. Martin, Chapel Hill, North Carolina.

       Permission to use, copy, modify, distribute, and sell this software and
       its documentation for any purpose is hereby granted without  fee,  pro-
       vided  that  the  above  copyright notice appear in all copies and that
       both that copyright notice and this permission notice  appear  in  sup-
       porting documentation, and that the name of Thomas Roell not be used in
       advertising or publicity pertaining to  distribution  of  the  software
       without  specific, written prior permission. Thomas Roell makes no rep-
       resentations about the suitability of this software for any purpose. It
       is provided "as is" without express or implied warranty.

       Thomas  Roell,  Kevin E. Martin, and Rickard E. Faith disclaim all war-
       ranties with regard to this software, including all implied  warranties
       of merchantability and fitness, in no event shall the authors be liable
       for any special, indirect or consequential damages or any damages what-
       soever  resulting  from  loss  of  use,  data or profits, whether in an
       action of contract, negligence or other tortious action, arising out of
       or in connection with the use or performance of this software.

       Author:  Thomas Roell, roellATinformatik.de

       Rewritten for the 8514/A by Kevin E. Martin (martinATcs.edu)
       Modified for the Mach-8 by Rickard E. Faith (faithATcs.edu)
       Rewritten for the Mach32 by Kevin E. Martin (martinATcs.edu)

       And here is my own copyright:

       This  driver is free software; you can redistribute it and/or modify it
       without any restrictions. This library is distributed in the hope  that
       it will be useful, but without any warranty.

       Copyright 1994 by Michael Weller

       Email addresses as of this writing:

       eowmobATexp-math.de mat42bATspi.de

       Michael  Weller  disclaims all warranties with regard to this software,
       including all implied warranties of merchantability and fitness, in  no
       event  shall Michael Weller be liable for any special, indirect or con-
       sequential damages or any damages whatsoever  resulting  from  loss  of
       use,  data  or profits, whether in an action of contract, negligence or
       other tortious action, arising out of or in connection with the use  or
       performance of this software.

       The mach32info(6) utility or demo reads out all configuration registers
       and the configuration EEPROM of your Mach32 card. If there is a problem
       with  the  particular card you have, compile and run the utility in the
       mach32/ directory of the svgalib distribution and send it's  stdout  to
       me  This might also be useful if you need a lot of options (e.g. clocks
       on new models?) to get it to work so that this can  be  done  automati-
       cally in future versions.

       I  got  a  few  reports about AST systems with onboard Mach32.  They do
       feature an incompatible EEPROM setup, but I think I  got  around  that.
       Nevertheless  the  Mach32 chipset driver doesn't work out of the box on
       any AST system I heard of.

       Since original ATI Mach32 demos and tools don't work as well,  I've  to
       claim  that  the  Mach32 on these AST systems does not conform to ATI's
       Mach32 docs.  Fortunately, Vernon  C.  Hoxie  <vernATzebra.com>
       found  a work around after years (really!) of investigating. AST Mach32
       seems to work now. The work around was also submitted to Xfree and will
       be  incorporated  to allow running it on the AST hardware too in recent
       versions. Please read on the misc_ctl command below.

       Dell users should have a look at the  vendor,  ramdac,  and  svgaclocks
       commands below (if they have problems with the default settings).

   Commands to support third party cards
       I  had  to  learn  that  those  cards seem to use not only non standard
       clocks for the Mach32, but also for the included SVGA.  However,  since
       people  often  like  to  use proprietary, non standard VGA (read 80x25)
       text modes, the Mach32 driver has to set the included  SVGA  to  a  VGA
       compatible  clock frequency. Otherwise svgalib has problems using plain
       VGA modes. This screws VGA modes up if these clocks have different val-
       ues on third party Mach32 cards.

       svgaclocks n
              with n a number between 0 and 31 to select the svga clocks to be
              used in vga modes. The bits of n refer to specific ATI  register
              bits  to  complicated  to explain here. Even if I would, I can't
              tell which clocks they would select on  your  third  party  card
              (which is the actual problem)

              svgaclocks 9 is the default setting and correct for original ATI

              Often svgaclocks 0 (Dell cards) works.

       svgaclocks keep
              is special in that the driver will not touch any  SVGA  timings.
              This  requires  the  Mach32  SVGA part to be in a VGA compatible
              mode when the svgalib application is started, that is, you  must
              use 80x25 (maybe 80x50) console text modes.

       As  I  mentioned  already,  Vernon  C.  Hoxie <vernATzebra.com>
       really seems to have located the reason for the  Mach32  AST  problems.
       Any access to MISC_CTL locks up the card & system. Fortunately MISC_CTL
       is only used for some DAC fine tuning (actually  the  setting  you  can
       fine  tune  with  the blank command) which is only of barely noticeable
       effect to the screen.

       The following configuration commands exist to support AST cards:

       misc_ctl keep-off
              Do not dare to touch MISC_CTL.

       misc_ctl use
              Use it for fine tuning of the Ramdac setup (default).

       Finally, for your convenience there exist:

       vendor ati
       vendor dell
       vendor ast
              These are macros that expand to settings for svgaclocks, ramdac,
              misc_ctl,  and  mach32eeprom  that  are usually correct for ATI,
              Dell, AST cards. Be aware that they  really  work  like  macros.
              That  is,  they  override  any  setting  of  svgaclocks, ramdac,
              misc_ctl, and  mach32eeprom  made  before  them  and  individual
              aspects  will  be  changed  by  a  following svgaclocks, ramdac,
              misc_ctl, and mach32eeprom command.

              Note that the mach32eeprom ignore required for some  Dell  cards
              requires  you to include explicit timings for Mach32 modes other
              than  640x480x256.   The  mach32/mach32.std-modes  file  in  the
              svgalib  distribution  contains  recommendations  for modes from

              I heard about a bug in some ATI chipsets returning wrong  memory
              amounts configs. (But cannot confirm that)

              You can enforce correct chipset identification from the configu-
              ration file:

       chipset Mach32 chiptype memory
              where chiptype is the sum of at exactly one value from  each  of
              the following two groups

              128    use no memory aperture.
              160    use a 1MB memory aperture.
              192    use a 4MB memory aperture.
              0      choose size for the memory aperture automatically.


              16     Ramdac is of type 0 (ATI68830)
              17     Ramdac is of type 1 (IMS-G173, SC11486)
              18     Ramdac is of type 2 (ATI68875, TLC34075)
              19     Ramdac is of type 3 (INMOS176, INMOS178)
              20     Ramdac is of type 4 (Bt481, Bt482)
              21     Ramdac is of type 5 (ATI68860)
              0      Ramdac type is queried from Mach32 chip.

              memory is the amount of video memory in KB.

       Note  that the type of the ramdac can be set more conveniently with the
       ramdac command.

       At least my VRAM card seems to be  very  peculiar  about  logical  line
       widths.  From  my  experience  a  multiple  of 64 pels is needed.  Your
       mileage may vary. Use the config file options to adjust it and tell  me
       if your card needs a different value. Include the name and model number
       of the card and what the correct numbers should be. This is so  that  I
       can correct the auto configuration of the driver.

       If  some  svgalib application has problems, note that you can force the
       logical line width to the default value from the config file.  Probably
       this will lead to glitches in some 800x600 resolutions. You can inhibit
       these resolutions from the config file as  well.  Apropos  glitches,  I
       found  no  guidelines  as  to  what  clock  rates  to use due to memory
       restrictions. I adjusted the driver, such that I get a  stable  pic  in
       all  resolutions.  However  sometimes  the screen is disturbed by heavy
       video memory accesses. If you don't like that, reduce the  clocks  used
       with  the  maxclock16  or maxclock24 command, resp.  This may of course
       lead to none of the predefined modes being used.  Then you can  try  to
       define your own mode via the define command.

       If you get some flicker or heavy noise on your screen, some fine tuning
       may be needed. My docs didn't give me hints as to what  each  card  can
       stand.   Especially  DRAM  cards may give problems (I've VRAM). In that
       case, use the fine tuning config commands  and  send  me  your  results
       along  with the output of mach32info(6).  Then I can include them in my
       next release.

   Fine-tuning configuration commands
       First you should think about the maxclock*  configuration  commands  to
       reduce pixel clocks used for each color depth.

       Especially  important  for  DRAM  cards is the video FIFO depth used to
       queue memory values for writing to the screen. Here is a command to set
       this value for the 8bpp modes:

       vfifo8 number
              where number is in range 0 - 15.  The default is now 6.

              Since  vfifo is of some impact to the speed of the card, tell me
              the lowest setting that satisfies your card.

              For 16/24/32 modes, there are non-zero values preset from inter-
              nal tables and the EEPROM, however you can enforce minimal vfifo
              values with:

       vfifo16 number
       vfifo24 number
       vfifo32 number

       blank number
              where number is 4 * pixel_delay + blank_adjust where pixel_delay
              and blank_adjust are in range 0 .. 3.  pixel_delay delays pixels
              before they are sent to the DAC  and  blank_adjust  adjusts  the
              blank pulse for type 2 DAC's.  blank should be set correctly for
              each DAC type automatically.  So use it only as a last resort.

       latch number
              where number is the sum of zero or more of  the  following  num-

              128    VRAM  serial  delay  latch enable, DRAM latch bits 63 - 0

              4096   Latch video memory data.

              8192   Memory data delay latch enable for data bits 63 - 0.

              16384  Memory full clock pulse enable.

              Default is to switch all settings on (they are on on my card  by
              default anyway).

       Note  that  these  commands  may  vanish  again once they are no longer
       needed for debugging purposes.

       There is no 320x200 mode in the EEPROM of the Mach32 at all, however  I
       defined one in the default configuration file for you. This is the best
       thing I could get up on my card/screen. Note that it will probably have
       big borders on your screen, and black lines in between the pixel lines.
       This is because of the lack of low clocks < 16MHz on the Mach32 and the
       lack of a line doubling mode as VGA has. The Mach32 is not intended for
       such low resolutions. If you find a better mode or have an idea, please
       let  me know. You can also just remove my timings from the default con-
       figuration file.

       Ah yes, about the EEPROM, I figured out how to read out the Mach32 EEP-
       ROM.  I did it by disassembling the BIOS routine mentioned in the docs.
       I then redid it in C. The driver will use everything it finds there.

       Use the Mach32 install tools (they should  have  reached  you  together
       with  your Mach32 VGA card) to setup your card/monitor combo correctly.
       The monitors setting from the config file (or default of 35kHz or some-
       thing) will be obeyed by the driver nevertheless (for safety!).

       As  you  probably know already, accessing the EEPROM causes some screen
       flickering. If this annoys you (or even worse your monitor) have a look
       at the mach32eeprom command described below. This allows you to put the
       data from the EEPROM into a file and which can be read whenever  it  is

       Don't  even think about changing the contents of the file. (There is an
       easily faked checksum in it.). Anyway the  driver  ensures  (hopefully)
       that no damage can be caused.

       Also, if some mode is not well aligned on your screen or you don't like
       it's sync frequency, consider using the Mach32 install  utility  (setup
       for  custom monitor) and set one up interactively. If there is no valid
       faster (higher VSYNC) standard mode given in the EEPROM the driver will
       use that mode. You will find that this is fun compared with calculating
       video timings for /etc/XF86Config or /etc/vga/libvga.config.

       However the install utility does restrict the maximum pixel  depth  for
       custom modes sometimes unneeded hard and the driver obeys that.  (Hmm..
       actually it should be smart enough to decide itself which  pixel  depth
       it  can  use  in that mode.)  Since the standard modes are usually only
       slightly shifted to one side a file  with  the  configuration  commands
       representing  the standard modes is given in mach32/mach32.std-modes in
       the svgalib distribution. You can use these as a starting point.

       But here are some real problems:

       I got 2 reports of people having problems with incorrect EEPROM  check-
       sums.   Both  had  motherboards  with  onboard Mach32 VGA's from AST. I
       guessed a checksum algorithm from those reports and  put  this  in  the
       code  in  addition  to  the standard ATI style. Still I got a report of
       someone whose EEPROM was completely empty. If you  have  problems  with
       checksums  send  me the output of mach32info(6) and I'll see what I can

       By default svgalib writes a complaining message and  ignores  the  con-
       tents.   You can have svgalib ignore the checksum and contents with the
       configuration command

       mach32eeprom ignore

       Then you can decide to use the partial info that is still in it. Use

       mach32eeprom ignore usetimings

       to use the video modes that are defined in the  EEPROM  (if  no  better
       modes  are  known  by  the  driver).  This is usually safe, because the
       driver knows which modes are safe for your hardware (if clocks, monitor
       and  ramdac are configured correctly). You can also allow the driver to
       use the configuration for the linear frame buffer in the EEPROM:

       mach32eeprom ignore useaperture


       mach32eeprom ignore usetimings useaperture

       However I discourage this because the driver will just enable what  the
       EEPROM  says about the aperture. Use mach32info(6) to check the address
       it will choose is safe. It might be better to use setuplinear to set up
       a 4MB aperture at a free address range.

       The mach32eeprom allows to work around these problems. Here is the com-
       plete description for this configuration command.

       mach32eeprom filename
              The filename has to begin with a "/".

              Unfortunately reading the EEPROM causes annoying screen flicker-
              ing  and  is slow.  To avoid this, specify a filename from which
              to read the contents of the EEPROM.

              If the file cannot be read, the EEPROM is read out and the  file
              is  created. There is a very simple checksum put into this file.
              Although it can easily be fooled, don't change the  file  except
              you know very, very well what you are doing.

              Also, as long as the file exists, changes in the Mach32's EEPROM
              are ignored. Delete the file to recreate an updated  version  on
              next  use  of svgalib. You should ensure that the permissions of
              the file don't allow normal users to change it. (This may happen
              if umask has a bad value when svgalib creates the file).


              mach32eeprom /etc/vga/mach32.eeprom

       Due to problems with some boards this command got heavily expanded:

       mach32eeprom subcommand1 [subcommand2...]
              At least one subcommand is needed. Valid subcommands are:

              ignore Don't  complain  about  checksum and don't use any EEPROM

                     Use the configuration for the memory  aperture  given  in
                     the EEPROM.

                     Use video modes found in the EEPROM of the board.

              nofile Forget  about any filename that maybe was already config-
                     ured.  Don't read a file, don't create one.

              file filename
                     New style form to specify the filename;  On  contrary  to
                     the  mach32eeprom  filename form it can be mixed with any
                     other mach32eeprom subcommand.

                     Don't read the file, always read the EEPROM (except  when
                     ignore is given) and create an uptodate image of the EEP-

                     Disable all previous updatefile commands.

                     Fall back to default behavior: If checksum on the  EEPROM
                     data is not ok, use nothing of the configuration data. If
                     it is ok, configure everything as specified in  the  EEP-

              The  subcommands  are  intended to be used together and are per-
              formed in the order specified. For example:

              mach32eeprom ignore useaperture usetimings

              will ignore the checksum of your EEPROM, but use  its  contents.
              Order is vital! So:

              mach32eeprom useaperture usetimings ignore

              won't  use  any  configuration from your EEPROM. Be careful with
              the useaperture subcommand. Please see the EEPROM WOES  section.
              Note  that  any  non  understood  subcommand  will terminate the
              mach32eeprom command  silently!  Use  only  one  subcommand  per
              mach32eeprom command to avoid this.

              The  mach32eeprom command is usually not allowed in the environ-
              ment variable SVGALIB_CONFIG.

       Due to poor design, Xfree86 insists on setting up the aperture  itself.
       It doesn't reset the original settings at a VC switch once it runs. You
       should not start X for the first time  after  a  boot  as  long  as  an
       svgalib  application is running. This will result in pre X values being
       restored at a VC switch by svgalib. If you use svgalib and  XF86_Mach32
       together,  run  X  first  or at least do not start it while any svgalib
       appl. is still running. After X was started once you  can  use  svgalib
       and X in all combinations w/o any problems. Xfree uses whatever address
       is given in the MEM_CFG Mach32 register for a 4MB aperture, even if the
       aperture  is  not  already  enabled  and  the value in this register is
       pointless garbage. This is IMHO a dangerous bug  as  some  systems  may
       work only with a 1MB aperture.

       However,  usage  of  a correct EEPROM circumvents any such problems. If
       you cannot use that, use mach32info (6) to find the address in MEM_CFG.
       Then,  if  it is a sensible setting for your system, enable a 4MB aper-
       ture at that address with setuplinear.  Ensure that no  other  card  or
       memory uses the address range you choose.

       This  version now has support for all accelerator functions of svgalib.
       However they were intended for use with the cirrus chips. It may happen
       that  at  runtime  they  find they cannot emulate the function actually
       requested. Then you should disable the corresponding blit function  (at
       least for that application) with the blit config command.

       Data transfer between the host and the Mach32 is normally via I/O. This
       proved to be pretty slow. If a big enough aperture is available, a sim-
       ple  memory  copy is used instead. This is usually much faster. You can
       change which method is used with the  blit  command.  This  I/O  option
       affects only vga_imageblt(3).  The other functions are incredible fast.

       For  type  2 DACS, there is support for 8 bit per color (instead of the
       normal 6) in the RGB triple in the color lookup table of the 256  color
       modes.  This  can  be enabled by an application, if it supports it. The
       testaccel(6) demo uses it if supported by your hardware.  You  can  use
       vga_ext_set(3) to use it from your programs.

       Mach32  Ramdacs  are specified by a type in range 1 .. 5. This type can
       be queried from the Mach32 and then specifies how to set up the ramdac.
       A  list  of actual hardware chips used for each type exists, but is not
       of much use. The Mach32 will return a type and the ramdac will be  com-
       pletely hardware compatible to one of the given type.

       Type 1 and 4 Dacs need different clock frequencies for high colormodes.
       For 32K/64K colormodes the frequencies have to be doubled and  for  16M
       colors (type 4 only) they have to be tripled. I followed the ATI scheme
       and did this internally. However this means that for  32K/64K  you  can
       use  only  clocks for which the doubled frequencies can be generated as

       This is no hard restriction as the 16  clocks  of  the  Mach32  can  be
       divided  by  2.  Thus if you setup some mode yourself try to use one of
       the divided clocks in your timings and I can use the  undivided  clocks

       It is a real restriction for 16M colors. ATI itself only supports 25MHz
       (640x480) here by use of a 75MHz clock. Depending on  your  clock  chip
       other  values  may  be  usable as well. Even the doubled/tripled clocks
       have to be less than the magic 80 MHz. However the driver does all this
       itself.  It  may just happen that some of the predefined or one of your
       handmade mode-timings can't be used because the clock that is used can-
       not be doubled/tripled.  Even though there is already some tolerance in
       the driver you may fix that by slightly changing the clock values  that
       you set with the clocks command. But note that this will as well affect
       the ability of the driver to calculate video timings and thus it  abil-
       ity to check the monitor and DAC safety restrictions.

       In  addition  (in  complete  contrast to my original ATI docs) RAMDAC 4
       does not support RGB with blue byte first but only with red first. This
       required  special  handling  and  me adding a bunch of functions to all
       modules of svgalib and vgagl. The added functions are of lower  perfor-
       mance  than the usual functions. However most data has to be completely
       mangled, so I doubt that it can be done much faster. Sorry.

       Of course, I might have forgotten to port some parts or  even  confused
       things.  About  bugs  in the gl and drawing libs, please ask Harm.  But
       then, I'm able to emulate a BGR ramdac on my card, so I should even  be
       able to reproduce your problems.

       Recently  I  hear  often  about type 6 ramdacs in non ATI Mach32 cards.
       There exists no info about these dacs, thus I cannot support them.  The
       driver  assumes  unknown  DACs  can stand up to 80MHz in 256 color clut
       modes and does not touch the ramdac (that is, assumes it is in the  256
       color mode already)

       To get rid of the warning message you can use the

       ramdac n
              configuration  command.  It allows to explicitly set the type of
              the dac to n (in range 0 to 5).  Ramdac 3 is  the  most  dumbest
              ramdac  possible,  s.t. you can use it without any fear for your

       ramdac dumb
              is equivalent to ramdac 3.

       ramdac auto
              switches back to the default autodetection.

       Some programs (which do not switch it off) will show a

       Using Mach32 version (sizeM at adrM (how), memK mem, DAC dactype)

       line. This will show up in testlinear(6) etc but will  probably  scroll
       away when you use vgatest(6).  In this line:

              is the version of the driver (as of my counting, not the svgalib

       size   is the size of the memory aperture. It can be 1  or  4  (1  will
              lead to not using the linear aperture if your card has more than
              1MB memory, however applications can still use the 1MB  aperture
              and  page  the  video memory through it in 1MB steps).  size can
              also be no if no aperture is setup at all.

       adr    is the base address of the aperture in MB.

       how    is autodetect if the aperture was setup this  way  already  when
              the  program  started.  It  is  setup  when  the the setting was
              enforced with a setuplinear configuration command. It is  EEPROM
              when  no aperture was detected, but parameters to set it up were
              found in the EEPROM.

       mem    is the amount of memory the card reported to have.

              is the type of the DAC that was detected.

              If a special ramdac type was set with the ramdac command a (set)
              will be displayed after dactype.

       If  mem, dactype and/or the chipset were enforced with chipset from the
       configuration file or vga_setchipsetandfeatures(3)  a  forced  will  be
       appended to the line.

       A  final  word: I have an ATI ULTRA PRO/2MB/EISA with a Type 2 DAC.  My
       monitor is an EIZO F550i-M. Everything I  tried  works  on  it  like  a
       charm.  However,  I couldn't try it with other machines myself and esp.
       other DAC's. Fortunately the Type 2 DAC is the worst to code. So I will
       probably have gotten the other DAC's right. But please be warned!

       I  did  my  very  best to code the driver to support the other DAC's by
       just reading the docs.  But i can't give any definitive  guarantee  for
       it to work or even not damaging your hardware. So please be careful!

       Note  that you will have to set the environment variable SVGALIB_MACH32
       to ILLTRYIT if your DAC is not type 0, 2, 3 or 4. This will  of  course
       change  if  no  one with a DAC equal to 1 or 5 has serious problems. If
       you have a different DAC, making patches to support your card  will  be
       much more helpful instead of just complaining.  If you have a different
       DAC that works well tell me as well such that I can remove the need for
       SVGALIB_MACH32 in the next release. Still, even now, after years, I got
       no reports of a Mach32 card with a type 1 or 5 ramdac. Go figure.

       Thank you for your audience and wishes you will enjoy this driver,


       svgalib(7), libvga.config(5), mach32info(6).

       The Mach32 driver and this documentation was written by Michael  Weller

Svgalib (>= 1.2.11)              1 August 1997               svgalib.mach32(7)