Certain Network Adapters Can Use DMA Channels 0-3 Only

When you use Microsoft Windows for Workgroups version 3.11 with a network adapter that uses direct memory access (DMA) in Slave DMA mode, only DMA channels 0, 1, 2, and 3 can be used.

NOTE: An example of a network adapter that uses Slave DMA mode is the Hewlett-Packard 27248A EtherTwist card.

If the card operates in Master DMA mode, it can work on any available DMA channel.

This problem is due to a limitation in the Windows for Workgroups 3.11 Virtual Direct Memory Access driver (VDMAD).

The only workaround is to use DMA channel 0, 1, 2, or 3 for your network adapter.

Microsoft has confirmed this to be a problem in the Microsoft Windows for Workgroups version 3.11 VDMAD driver. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.