README.NT                    MATROX GRAPHICS INC.            December 11, 1996

                                  Matrox MGA
                          Drivers for Windows NT 4.0
                                 on x86 CPUs
                            Rev. 2.30.002 (4.0.2)

-This driver is fairly stable for the PCI boards however, there are a
few problem with jitter and corruption on the VL and AT boards. Therefore,
users are recommended to use the Microsoft NT 4.0 driver that can be
found on the OS CD-ROM and the 2.30 driver should be used by those who
require dual screen support.



Windows NT Files on this Disk
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   \MGAV.TAG            Driver version identification file
   \MGAV.INF            MGA driver installation file for Windows NT
   \MGAV.SYS            MGA miniport driver
   \MGAV.DLL            MGA display driver
   \README.NT           This file

   \MGASET.CPL          Monitor selection applet for Control Panel
   \MONDLG.DLL          DLL required by the Monitor selection applet
   \MGA.MON             MGA monitor file
   \MGAVGA.EXE          Utility used to initialize the MGA to VGA mode
   \SETUP.EXE           Installation utility for MGA applets and drivers


About These Drivers
~~~~~~~~~~~~~~~~~~~
These drivers support all Matrox MGA Ultima, Ultima-Plus, Impression,
Impression-Plus, Impression-Pro, and Impression-Lite boards.

These drivers are not the same as the ones supplied on the installation
disks of Windows NT 4.0.  Here are the main differences:

      These drivers                   Drivers supplied by Microsoft
      -----------------------------   -----------------------------
      16 bits-per-pixel modes         16 bits-per-pixel modes
      support 64k colors              support 32k colors
      -----------------------------   -----------------------------
      Dual-board configurations       Dual-board configurations
      are available                   are not available
      -----------------------------   -----------------------------
      Display refresh rates are       Display refresh rates are
      set through the MGA Monitor     set through the Display
      applet or through the Display   applet
      applet
      -----------------------------   -----------------------------
      DDC is not supported            DDC is not supported
      -----------------------------   -----------------------------

Switching from one set of drivers to the other is possible.  However, the
different way of setting refresh rates may cause a warning about an invalid
resolution being requested.  This warning could appear when the system is
rebooted after switching drivers, and it should go away if the mode to be
used is reset through the Display applet.

Installation
~~~~~~~~~~~~
Refer to your MGA Owner's Manual to install your MGA board(s) in your
system.

If you are installing two MGA boards in your system, please note that
only one should be VGA-enabled through the on-board switch.  Dual-
board installations are similar to a single board installation.  The
system will automatically assign separate addresses to each PCI board
allowing the driver to distinguish between the two boards.  In a dual-
board configuration, both boards must run with the same resolution and
pixel-depth.  It is recommended that no ISA board be mapped at 0xAC000
in a multi-board setup.

If both PCI and VLB/ISA MGA boards are installed in your system, you can
achieve better performance by following a few simple rules:

      - The VGA-enabled board should be, in order of preference:
                1. the more capable PCI board;
                2. any PCI board;
                3. the more capable VLB board;
                4. any VLB board;
                5. the more capable ISA board;
                6. any ISA board.

      - Among VLB and ISA boards, set the mappings of the VLB boards so that
        they are lower than the mappings of the ISA boards.  The available
        mappings are, in ascending order:  0xAC000, 0xC8000, 0xCC000,
        0xD0000, 0xD4000, 0xD8000, and 0xDC000.

      - Among VLB boards, set the mappings of the more capable boards so that
        they are lower than the mappings of less capable boards.  Proceed
        similarly among ISA boards.

These rules will allow the driver to use the high-performance PCI and VLB
boards instead of the slower ISA boards whenever possible.  In general,
the 'more capable' boards are those that hold more memory.  However, you
may decide that some other capability, such as true color output, is more
important to your work, and you may set a different order among the VLB or
ISA boards.

To install the MGA drivers, run the Setup utility supplied with the drivers:

      - Start the Windows NT Explorer, or open a Command Prompt window.

      - Go to the drive and directory holding the driver installation files.

      - Double-click on the Setup application, or type 'setup' and press 
        Enter.

The Setup utility will install the MGA Monitor applet and the drivers 
automatically.  You must restart your computer before the changes take effect.

The general procedure for changing a display driver is the following: 
 
      - Right-click on the desktop, select 'Properties'.  This will open 
        Display Properties.

      - Select the 'Settings' tab.
 
      - Press the 'Display Type...' button. 
 
      - In the Display Type dialog box, press the 'Change...' button. 
 
      - In the Change Display dialog box, press the 'Have Disk...' button. 
 
      - In the Install From Disk dialog box, type the location of the 
        MGA installation files (e.g. "A:\" or "D:\WINNT"). 
 
      - From the displayed list, select the model of your display adapter, 
        and press 'OK'.

      - Answer 'Yes' to the Third-party Drivers dialog box. 
 
      - Press 'OK' in the Installing Driver message box. 

      - Press 'Close' in the Display Type dialog box.

      - Press 'Close' in the Display Properties applet.

      - In the System Settings Change dialog box, you should select 'Yes' 
        so that the new settings take effect. 
 
With older BIOSes, running a full-screen Command Prompt application in a
single-screen system requires that MGAVGA.EXE be executed at the start of
the DOS session.  MGAVGA.EXE has been copied into the SystemRoot\SYSTEM32
subdirectory at installation time, where SystemRoot stands for your Windows
NT installation path (SystemRoot is an environment variable:  its value will
be in the list displayed when the command 'set' is typed in a Command Prompt
session).  To make sure that MGAVGA is run automatically at the start of each
Command Prompt session, you can include the following line in your 
AUTOEXEC.NT file:

        %SystemRoot%\system32\mgavga

Changing resolution 
~~~~~~~~~~~~~~~~~~~ 
Whenever you want to change resolution, open Display Properties / Settings. 
The available modes are displayed through the 'List All Modes...' button. 
 
If you are using a dual-screen configuration, the driver will spread the 
desktop over two monitors.  Special dual-screen resolutions will be 
listed, where the horizontal or vertical resolutions are multiple of their 
normal size.  Selecting one of these resolutions will permit testing of 
both monitors. 

Monitor Customization
~~~~~~~~~~~~~~~~~~~~~
There are two ways to select refresh rates for your monitor.  Whenever
a new driver is installed, it is assumed that refresh rates are selected
through the ControlPanel/MGA Monitor applet.  If your preference goes to
selecting refresh rates through the 'Refresh Frequency' field of the
ControlPanel/Display applet, you will have to edit a value in the Registry.
Both options are described below.  The section 'Editing the Registry' gives
details on how to modify this value.

After installation, the display driver assumes that refresh rates will be set
through the MGA Monitor applet.  However, since the applet has not been run
yet, the driver will assume that your monitor is capable of handling all
resolutions from 640x480 up to 1600x1200 at a 60 Hz refresh rate.  If your
monitor does not support the higher resolutions, or if it is capable of
higher refresh rates, you can run the ControlPanel/MGA Monitor applet and
select a suitable monitor from the list.  This will ensure that your monitor
will not be over-driven, and that you will get the benefits of higher refresh
rates.

The MGA Monitor applet should have been copied by the Windows NT Setup
program into your SystemRoot\SYSTEM32 subdirectory when the MGA drivers
were installed.  To customize your monitor:

      - Click on Start/Settings/Control Panel.

      - Open the MGA Monitor applet.

      - From the list of monitors, select the appropriate monitor, or one
        whose maximum refresh rate matches the one you are using.  An
        MGA.INF file will be created in the SystemRoot\SYSTEM32
        subdirectory.

To make sure that the newly created MGA.INF is correct for your monitor:

      - Right-click on the desktop, select 'Properties'.  This will open 
        Display Properties.

      - Select the 'Settings' tab.
 
      - Select the resolution and pixel depth you wish to test.

      - Press the 'Test' button.  The test will use the video parameters
        appropriate for the monitor selected in MGA Monitor.

If your monitor does not display a stable test screen, then the parameters
set by MGA.INF are not suitable for your monitor.  Press the 'Cancel' button
to close Display, run MGA Monitor again to select another monitor from the
list, and repeat the Display test.

If the test screen is not displayed, but you get instead a message box about
the screen not being visible due to a limitation of your video card or
display monitor, then it is probable that the tested resolution (say,
1280 x 1024) was above the limit set by MGA.INF (say, 1024 x 768).  If your
monitor is capable of the higher resolution, then run MGA Monitor again to
select an appropriate monitor.

The new MGA.INF will take effect when you restart Windows NT.  Any resolution
higher than the set limit will not appear in the Display applet mode list.
Deleting MGA.INF will remove all monitor limits to the resolution, although
the refresh rate will default to 60Hz.

In a dual-board configuration, both boards will output the same refresh
rate to each monitor.  It is recommended that the monitor selected in MGA
Monitor be compatible with the less capable monitor in your setup.

If you would rather select refresh rates through the ControlPanel/Display
applet, set the 'User.MgaInfoFile' value in the Registry to 0 (see the
'Editing the Registry' section for details).  The next time you reboot,
refresh rates available for each mode will be returned to the Display
applet.  The system will probably reboot in the 640x480x8 mode, and a
warning message will be displayed.  This is normal, since the system could
not find the hardware default setting that was used previously for refresh
rates.  You can now select refresh rates from the list displayed by
ControlPanel/Display.  You should test any new mode to make sure that your
monitor actually supports the new resolution/refresh rate combination.

In a dual-board configuration, both boards will output the same refresh
rate to each monitor.  The less capable monitor in your setup will determine
the maximum refresh rate.

Editing the Registry
~~~~~~~~~~~~~~~~~~~~
Information held in the Windows NT Registry can have a direct effect on the
whole system.  Introducing incorrect values can cause serious problems and
may make it necessary to reinstall Windows NT.  The changes outlined below
should have effects limited to the MGA drivers.  However, if you accidentally
modify values that make your system unusable, please note that it is often
possible to undo the damage by using the 'Last Known Good Configuration'
option at boot time.

Modifying keys and values in the Registry is done through the Registry
Editor.  The Registry Editor can be invoked in the following way:

      - Open Explorer or a Command Prompt window.

      - CD to the SystemRoot\SYSTEM32 subdirectory.

      - Double-click on regedt32, or type 'regedt32'.  The Registry Editor
        will come up.

To modify the values that govern the behavior of the MGA driver:

      - Select the HKEY_LOCAL_MACHINE window.

      - Travel down to the key named:
        HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\mgav\Device0.

In the right window pane, you will find many values.  The only value that
should be modified is:

User.MgaInfoFile    when set to 1, allows use of the MGA Monitor applet
                    to control refresh rates.  A value of 0 will allow the
                    Display applet to list available refresh rates.  See
                    the 'Monitor Customization' section for more details.

                    The default value of User.MgaInfoFile is 1.

If you wish to change this value:

      - Double-click on the selected value.

      - In the DWORD Editor, change the value to '0' or '1'.  The new value
        will take effect the next time you reboot.

Board Testing
~~~~~~~~~~~~~
If you encounter any problem running Windows NT with your board, you should
first determine whether it is a system or hardware problem.  The best way
to check for a potential hardware problem is to use the MGA Setup program.

SETUP is a DOS program included on Disk #1 of the Power Driver package.
It cannot be run from a Windows NT Command Prompt session.

If you have a DOS (FAT) partition on your hard disk, simply install the
Setup and Utilities product using the provided Installation program.  Then
go to the \MGA\SETUP program and type SETUP.

If you do not have a DOS partition, you will have to create a bootable
disk with SETUP on it. Here is the procedure:

      - Insert Power Driver disk#1 in your diskette drive
	   - copy a:\setup\files1.zip and a:\pkunzip.exe to your hard disk
	   - type "pkunzip files1" to unzip the files
	   - format a DOS bootable disk
	   - copy the following files to your new floppy disk:
	     SETUP.EXE, DOS4GW.EXE, MGA.MON
      - Reboot your computer with the the new diskette
	   - type "setup"

In SETUP, select "Graphic Mode Test" to test the different modes available
for your board.  The program will not attempt to test a mode which is not 
supported by your board. The default testing will be done at a 60Hz refresh 
rate for all resolutions.

If you have a customized monitor file (MGA.INF) in your SystemRoot\SYSTEM32 
subdirectory, SETUP can take it into account, if you set the MGA environment 
variable as follows:

      set mga=SystemRoot\system32

where SystemRoot stands for your Windows NT installation path.

Known Bugs and Limitations
~~~~~~~~~~~~~~~~~~~~~~~~~~
      - It is currently impossible to recover from a display test performed
        using an unsuitable MGA.INF file.  Apparently, the new on-the-fly
        mode switching feature of Windows NT has prompted changes that affect
        the restoration of the original mode, and the driver is forced into
        using the new MGA.INF settings instead of the previous ones.  If you
        select a monitor that makes your system unusable, you will have to
        reboot to DOS or to Windows NT VGA mode and delete the MGA.INF file
        from your SystemRoot\SYSTEM32 directory.

      - Running a full-screen Command Prompt application in a single-screen
        system might not work quite as expected.  If you encounter problems,
        try running MGAVGA.EXE at the start of the DOS session.  You can
        include this program in the SystemRoot\SYSTEM32\AUTOEXEC.NT batch
        file, so that it is run automatically at the start of each Command
        Prompt session.

      - We are aware of conflicts between the MGA boards and some SCSI
        adapters.  The cause of these conflicts has not been determined yet.
        In our experience, there are some conbinations of addresses that do
        work.



Other known bugs:

	- MGA-ULT/1/A
	  Application:  Hardware cursor 
	  Resolutions:  All at 16bpp
	  Comment: Random flickering

	- MGA-PRO/4.5Z/V
	  Application:  All
	  Resolutions:  All
	  Comment: Hard drive access causes screen jittering.

	- MGA-PRO/4.5Z/V
	  Application: Full Screen Dos to any Windowed mode
	  Comment: Cannot Alt-Enter 

	- MGA-IMP/3Z/A, MGA-VLB/2, MGA-ULT/1/A
	  Application: 'Mystify' screen saver
	  Resolutions:  All at 8bpp
	  Comment: Jitter on edge of objects.

	- MGA-PCI/4/200 
	  Application: Mouse 'Jack-in-the-box' animation	  
	  Resolutions: All
	  Comment:  Moving a display window corrupts animation

	- MGA-PRO/4.5Z/V, MGA-ULT/2/V
	  Application: 'Blank Screen'  screen saver (preview)
	  Resolutions: All
	  Comment: NTVDM Error
	  
	- MGA-PRO/4.5Z/V	
	  Application: MGAVGA.EXE (DOS Apllication)
	  Resolutions:  All
	  Comment:  NTVDM Error
	
	- MGA-IMP Series
	  Application: Switch display mode and shutdown
	  Resolution: All
	  Comment: 'Shutdown' message corrupted
	  
	- MGA-IMP+/P 
	  Application: CorelDraw V.6 
	  Resolution: 1024x768x16
	  Comment: Desktop flickers when dragged around screen if the square 
		   or ellipse tool is used

