119
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
Summary of Contents for Vectra VL800
Page 1: ...hp vectra vl800 desktop minitower technical reference manual www hp com go vectrasupport ...
Page 26: ...26 1 VL800 Desktop Documentation ...
Page 44: ...44 2 VL800 Minitower Documentation ...
Page 122: ...122 6 HP BIOS BIOS Addresses ...
Page 138: ...138 7 Tests and Error Messages Error Message Summary ...