HP Vectra VEi8 HP Vectra VEi8, Technical Reference Manual (Product Description - Page 38

3 BIOS Overview BIOS Addresses Applies only if a supplementary ISA card is installed I/O Address Ports 03B0 - 03DF 03E8 - 03EF 03F0h- 03F5 03F6 03F7 03F8 - 03FF 04D0 - 04D1 0678 - 067B 0778 - 077B 0CF8 - 0CFF Function VGA COM3 Floppy disk drive controller IDE primary channel Floppy disk drive controller COM1 Interrupt edge/level control LPT2 ECP LPT1 ECP PCI configuration space 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. DMA controller Channel Function 0 Free 1 Free if not used for parallel port or audio in Setup1 2 Floppy disk controller 3 Free if not used for parallel port or audio in Setup2 4 Used to cascade DMA channels 0-3 5 Free 6 Free 7 Free 1. DMA 1 is used for the parallel port by default 2. DMA 3 is used by audio by default 38