HP Vectra VL800, Техническое справочное руководство

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6 HP BIOS
BIOS Addresses
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.
0378 - 037F LPT1
03B0 - 03DF VGA
03F0 - 03F5 Floppy disk drive controller
03F6 IDE primary channel
03F7 Floppy disk drive controller
03F8 - 03FF COM1
04D0 - 04D1 Interrupt edge/level control
0778 - 077F LPT1 ECP
0CF8 - 0CFF PCI configuration space
C000 - Power Management I/O space and ACPI Registers
Default Values for
I/O Address Ports
Function
DMA controller
Channel Function
DMA 0 Free
DMA 1 Free if not used for parallel port in
Setup
DMA 2 Floppy disk drive controller
DMA 3 Free if not used for parallel port in
Setup
DMA 4 Used to cascade DMA channels 0-3
DMA 5 Free
DMA 6 Free
DMA 7 Free