Dma Channel Controllers - HP Vectra VL600 Technical Reference Manual

DMA Channel Controllers

Only "I/O-to-memory" and "memory-to-I/O" transfers are allowed.
"I/O-to-I/O" and "memory-to-memory" transfers are disallowed by the
hardware configuration.
The system controller supports seven DMA channels, each with a page
register used to extend the addressing range of the channel to 16 MB. The following table
summarizes how the DMA channels are allocated.
Channel
0
1
2
3
4
5
6
7
DMA controller
Function
Free
Free if not used for parallel port in Setup
Floppy disk controller
Free if not used for parallel port in Setup
Used to cascade DMA channels 0-3
Free
Free
Free
4 BIOS Overview
BIOS Addresses
47