A SERVICE OF

logo

80
4 Summary of the HP/Phoenix BIOS
BIOS Addresses
HP I/O Port Map (I/O Addresses Used by the System
1
)
Peripheral devices, accessory devices and system controllers are accessed
via the system I/O space, which is not located in system memory space. The
64 KB 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).
The following address map is not BIOS dependent, but is determined by the
operating system. However, the Setup program can be used to change some
settings. Beware that some of the I/O addresses are allocated dynamically.
1. If configured (legacy resources only).
I/O Address Ports Function
0000h - 000Fh DMA controller 1
0020h - 0021h Interrupt controller 1
0040h - 0043h Interval timer 1
0060h, 0064h Keyboard controller
0061h System speaker, or NMI status and control
0070h NMI mask register, RTC and CMOS address
0071h RTC and CMOS data
0081h - 0083h, 008Fh DMA low page register
0092h Alternate reset and A20 Function
00A0h - 00A1h Interrupt controller 2
00C0h - 00DFh DMA controller 2
00EAh - 00EBh Internal port
00F0h - 00FFh Co-processor error
0102h Graphics controller (Matrox MGA)
0170h - 0177h IDE hard disk drive controller secondary channel
01F0h - 01F7h IDE hard disk drive controller primary channel
0200h - 0207h Joystick port (Soundblaster)