HP XA HP I/O Port Map (I/O Addresses Used by the System1), Function, I/O Address Ports

4 HP BIOS

BIOS Addresses

HP I/O Port Map (I/O Addresses Used by the System1)

Peripheral devices, accessory devices and system controllers are accessed via the system I/O space, which is not located in system memory space. The

64KB of addressable I/O space comprises 8-bit and 16-bit registers (called I/O ports) located in the various system components. When installing an accessory board, ensure that the I/O address space selected is in the free area of the space reserved for accessory boards (100h to 3FFh).

Although the Setup program can be used to change some of the settings, the following address map is not completely BIOS dependent, but is determined partly by the operating system. Note that some of the I/O addresses are allocated dynamically.

	I/O Address Ports	Function
0000	- 000F	DMA controller 1
0020	- 0021	Master interrupt controller (8259)
002E - 002F		NS-317 Configuration registers
0040	- 0043	Timer 1
0060, 0064		Keyboard controller (reset, slow A20)
0061		Port B (speaker, NMI status and control)
0070		Bit 7: NMI mask register
0070	- 0071	RTC and CMOS data
0080		Manufacturing port (POST card)
0081	- 0083, 008F	DMA low page register
0092		PS/2 reset and Fast A20
0096	- 0097	Little Ben
00A0 - 00A1		Slave interrupt controller
00C0	- 00DF	DMA controller 2
00F0 - 00FF		Co-processor error
0130	- 013F	AD1816 sound system
0170	- 0177	IDE secondary channel
01F0 - 01F7		IDE primary channel
0200	- 0207	AD1816 Joystick port
0220	- 0232	AD1816 Soundblaster
0278	- 027F	LPT 2
02E8 - 02EF		Serial port 4 (COM4)
02F8 - 02FF		Serial port 2 (COM2)
0372	- 0377	IDE secondary channel, secondary flexible disk drive

1.If configured.

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