HP 525 5/XX, 520 5/XX manual DMA Channel Controllers Bios version GJ.07.xx, 0778-077A, 106

4 Summary of the HP/Phoenix BIOS

HP/Phoenix BIOS (BIOS version: GJ.07.xx)

I/O Address Ports	Function	Bits
03BC-03BF	Parallel Port 1
03F0--03F5-03F7	Integrated Floppy Disk Controller
03F8-03FF	Serial Port 1
03E8-03EF	Serial Port 3
0CF8-0CFF	Used for PCI Configuration1
0496-0497	HP Reserved
0678-067A	Parallel Port if ECP Mode is Selected
0778-077A	Parallel Port if ECP Mode is Selected

1.These addresses are dedicated to configuration registers for PCI devices.

Addressing System Board Components (BIOS version: GJ.07.xx)

This section provides further details of how the BIOS uses the system board components mentioned in the I/O port list.

DMA Channel Controllers (BIOS version: GJ.07.xx)

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.

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