Switch 2/4: bus master DMA enable/disable

The position of switch 2/4 has no effect if the Ringnode is installed in an 8-bit slot or if switch 2/5 is OFF. Bus master DMA is not possible in these circumstances.

Switch 2/4 Bus master DMA

ON (Default) Enabled

OFF Disabled

You must use 16-bit mode if you are installing the Ringnode in a Novell NetWare 4.x or 3.x server. The following table summarizes the types of data transfer associated with different combinations of switches 2/4 and 2/5, and with the Ringnode in an 8- or 16-bit expansion slot:

Switch settings 8-bit slot 8-bit slot 16-bit slot 16-bit slot

Switch 2/4 setting ON OFF ON OFF

Switch 2/5 ON c c a b

Switch 2/5 OFF c c c c

Types of data transfer associated with different settings of switches 2/4 and 2/5

a = 16-bit bus master DMA

b = 16-bit I/O transfer

c = 8-bit I/O transfer

Switch 2/4	Bus master DMA
ON (Default)	Enabled
OFF	Disabled

Switch settings	8-bit slot	8-bit slot	16-bit slot	16-bit slot
Switch 2/4 setting	ON	OFF	ON	OFF
Switch 2/5 ON	c	c	a	b
Switch 2/5 OFF	c	c	c	c

a	=	16-bit bus master DMA
b	=	16-bit I/O transfer
c	=	8-bit I/O transfer