BIOS I/O PORT MAP
This section describes the HP BIOS port map. The next section provides more details about
how the BIOS uses the system board components mentioned in the I/O port list.
I/O Address Ports
Function
Bits
0000-000F
DMA controller 1
8
0020-0021
Interrupt controller 1
8
0040-0043
Interval timer 1
8
0060, 0064
Keyboard controller
8
0061
NMI status and control
8
0070
NMI mask register, RTC address
8
0071
RTC data
8
0081-0083, 008F
DMA low page register
8
0092
Alternate reset and A20 Function
8
0096-009F
Internal ports
8
00A0-00A1
Interrupt controller 2
8
00C0-00DF
DMA controller 2
8
00F0-00FF
Co-processor error
0170-0177
IDE controller secondary channel
01F0-01F7
IDE controller primary channel
0278-027F
Parallel port 3
02E8-02EF
Serial port 4
02F8-02FF
Serial port 2
0370-0375
Secondary flexible disk controller
0376
IDE controller secondary channel
0377
Secondary flexible disk controller
0378-037F
Parallel port 2
03B0-03BB
Integrated video graphics controller
03BC-03BF
Parallel port 1
03C0-03DF
Integrated video graphics controller
03E8-03EF
Serial port 3
03F0-03F5
Flexible disk controller
03F6
IDE controller primary channel
03F7
Flexible disk controller
03F8-03FF
Serial port 1
0CF8-0CFF
Used for PCI configuration*
*These addresses are dedicated to configuration registers for PCI devices.