Assign IRQ Manually

Most Matrox cards need an allocated IRQ.  It is recommended not to configure another device on the same IRQ as the Matrox card.

If the system doesn't allocate an IRQ to the Matrox card, try to obtain a motherboard BIOS update (and instructions for its installation) from the motherboard manufacturer.

On some systems it may be necessary to move the Matrox card to a different PCI slot, because not all slots on certain motherboards support bus mastering.  Refer to your motherboard manual for more information about IRQ allocation and bus mastering.  Manuals are often available in electronic form from the motherboard manufacturer's web site.

In some cases it may be necessary to manually assign an IRQ through the motherboard BIOS.  Many motherboard BIOSs have an option to "Assign an IRQ to VGA" or "VGA IRQ" or "Assign IRQ to PCI VGA". These options should be enabled in the case of graphics cards; however, simply enabling these options  won't automatically assign an IRQ to the m3D card -- refer to your motherboard manual for a detailed explanation how to do that through the PCI configuration menu of the motherboard BIOS.)

IRQSET for Matrox graphics cards

Another way to assign an IRQ to a Matrox card is with the IRQSET.EXE utility, which is installed in C:\Program Files\Matrox MGA PowerDesk during Matrox PowerDesk driver installation.

Note: The IRQSET utility only functions in Windows 95 and Windows 98. It will not work in Windows NT or any other operating system.  In addition, your motherboard must have an Intel chipset and must be PCI 2.1 compliant. 

To locate an available IRQ, right-click "My Computer", then click "Properties" => "Device Manager", and double-click the computer icon at the top of the list. In "Computer Properties", find an available IRQ between 10 and 15. Then open your "autoexec.bat" file for editing.  To do this, click "Start" => "Run" and type "sysedit" (no quotation marks), then click "OK". In the "Autoexec.bat" window, type the following BEFORE the first line: 

C:\Progra~1\Matrox~1\IRQSET X 0 S

Replace "X" with "A" for IRQ 10, "B" for IRQ 11, "C" for IRQ 12, "D" for IRQ 13, "E" for IRQ 14 and "F" for IRQ 15.  (However, IRQs 13, 14 and 15 are typically allocated to system devices and if so, are unavailable.)

Press [Enter], then save the file and reboot.

IRQSET3 for Matrox m3D and Rainbow Runner Studio

The Matrox m3D and Rainbow Runner Studio (not G-Series) cards require a different version of IRQSET  called IRQSET3.EXE, which can be found only on our web site. For Help on IRQSET3, type "IRQSET3" (no quotation marks) at the DOS prompt.

IRQSET3 for the m3D:
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To locate an available IRQ, right-click "My Computer", then click "Properties" => "Device Manager", and double-click the computer icon at the top of the list. In "Computer Properties", find an available IRQ between 10 and 15. Then open your "autoexec.bat" file for editing.  To do this, click "Start" => "Run", and type "sysedit" (no quotation marks), then click "OK". In the "Autoexec.bat" window, type the following BEFORE the first line:

C:\[PATH]\IRQSET3 -i X -p -o

Replace "X" with "A" for IRQ 10, "B" for IRQ 11, "C" for IRQ 12, "D" for IRQ 13, "E" for IRQ 14 and "F" for IRQ 15. (However, IRQs 13, 14 and 15 are typically allocated to system devices and are unavailable.)

Press [Enter], then save the file and reboot.

IRQSET3 for the Rainbow Runner:
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The main reason to use IRQSET3 with Rainbow Runner is to set the IRQ to "Level" and not "Edge".  The Rainbow Runner won't run if the IRQ is activated on "Edge".  Check your motherboard BIOS for an option that reads:

IRQ Activated by:   Edge/Level

If the option exists, choose "Level" and don't use IRQSET for this purpose.

To see if the IRQ assigned to the Matrox card is at "Edge" or "Level", type the following command at the DOS prompt:

IRQSET3 -d

If you find that the IRQ is set to "Edge" and the BIOS doesn't have the capacity to change the setting, then type the command as follows:

IRQSET3 -l

Next, type the command as follows:

IRQSET3 -d

If the setting still doesn't change, try each of the following until you find one that will change the setting:

IRQSET3 -i A -o -r A -l
IRQSET3 -i B -o -r B -l
IRQSET3 -i C -o -r C -l
IRQSET3 -i A -o -r B -l
IRQSET3 -i A -o -r C -l
IRQSET3 -i B -o -r A -l
IRQSET3 -i B -o -r C -l
IRQSET3 -i C -o -r A -l
IRQSET3 -i C -o -r B -l

When you find the correct command sequence to change the setting, add it to your "autoexec.bat" file.  To do this, click "Start" => "Run" and type "sysedit" (no quotation marks), then click "OK". In the "Autoexec.bat" window, type the correct command sequence, then press [Enter]. Save the file and reboot to apply the changes.

Frequently asked questions about IRQSET:

Do commands need to be in upper or lower case?

Answer: All commands using the "-" (dash) symbol must be in lower case; all commands that don't use a dash must be in upper case (capitalized).

Why do I get a "Bad Command or File Name" message when I run IRQSET?

Answer: Chances are IRQSET isn't in the directory you are currently in.  Verify the location of the file and make sure you're in the same directory.  In the case of an "autoexec.bat" command line, make sure the full path is specified and that long file names have been enclosed in quotation marks or truncated accordingly.

Why don't my commands work with the m3D or Rainbow Runner Studio?

Answer: Make sure you have IRQSET3 version 1.2.1 by typing in IRQSET3 alone on a command line, that will tell you the version you are using.
IMPORTANT: IRQSET and IRQSET3 work only in Windows 95 and Windows 98. They will NOT work under any other operating system.
