Resources - Direct Memory Access (DMA)

DMA enables devices to work around the processor to do other work and the peripherals to transfer data themselves increasing performance.  Channels were created in the chipset    circuitry    to    control    the    transfer   of

information. DMA channels are only on the ISA bus. PCI devices do not use standard DMA channels at all. The table below provides summary information about the DMA channel numbers in a typical computer. You may find this table useful when considering how to configure your system or for resolving DMA conflicts.

DMA	Bus	Default Use	Optional Uses
0	none	Memory Refresh	None
1	8/16-bit	Sound card (low)	ECP Parallel ports SCSI host adapters Tape controllers Sound card (low) Ethernet cards
2	8/16-bit	Floppy controller	Tape accelerator cards
3	8/16-bit	None	ECP Parallel ports SCSI host adapters Tape controllers Sound card (low) Ethernet cards
4	none	Cascade for DMAs 0-3	None
5	16-bit	Sound card (high)	SCSI host adapters Ethernet cards
6	16-bit	None	Sound cards (high) Ethernet cards
7	16-bit	None	Sound cards (high) Ethernet cards