VESA Local Bus Device Conflicts in Windows NT (138738)


The information in this article applies to:

  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 3.51
This article was previously published under Q138738

SUMMARY

When you use VESA local bus devices in a Windows NT computer with a fast processor, one of the following STOP error messages may appear:
STOP 0x0000000A
IRQL_NOT_LESS_OR_EQUAL
STOP 0x0000007F
UNEXPECTED_KERNEL_MODE_TRAP
STOP 0x00000050
PAGE_FAULT_IN_NONPAGED_AREA

RESOLUTION

To correct this problem, do one of the following:
  • Disable the external cache on the computer. Some BIOS manufacturers include tuning parameters in the CMOS setup.

    -or-
  • Add wait states to the L2 cache in the computer CMOS setup. This adjustment may compensate for slower devices.
For detailed information on the hardware, contact your computer manufacturer.

MORE INFORMATION

A maximum of three VESA local (VL) bus connections can reside on a motherboard. Each slot contains up to one VL-bus device. For example, if a VL-bus device such as a video controller physically resides on the motherboard, only two VL-bus slots are then allowed in the system. The following table lists recommended maximum number of slots at various buffered or unbuffered speeds: 

  CPU Speed                    Unbuffered        Buffered
   --------------------------------------------------------------

   Less or Equal to 33 MHz      2 slot/2 device   3 slot/3 device
   At 40 MHz                    1 slot/2 device   not recommended
   Greater or Equal to 50 MHz   0 slot/2 device   not recommended
Modification Type:MinorLast Reviewed:6/23/2005
Keywords:KB138738
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