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5 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.
0388 - 038B
03B0 - 03DF VGA
03E8 - 03EF
03F0 - 03F5
03F6 IDE primary channel
03F7 Flexible disk drive controller
03F8 - 03FF COM1
04D0 - 04D1 System board resources under Windows 95
0678 - 067B
0778 - 077B LPT1 ECP
0CF8 - 0CFF PCI configuration space
8000 -
8400 -
8800 -
Default Values for
I/O Address Ports
Function
DMA controller
Channel Function
DMA 0 Free
DMA 1 Free
DMA 2 Flexible disk drive controller
DMA 3 LPT ECP
DMA 4 DMA controller
DMA 5 Free
DMA 6 Free
DMA 7 Free