I/O ADDRESSES USED BY THE SYSTEM*
Peripheral devices, accessory devices and system controllers are accessed via the system I/O
space. The 64 KB of addressable I/O space comprises 8-bit and 16-bit I/O ports (these are
registers that are located in the various system components). When installing an accessory
board, ensure that theI/O address space selected is in the free area of the space reserved for
accessory boards (100h to 3FFh).
*If configured.
170h-177h, 376h
IDE controller secondary channel
1F0h-1F7h, 3F6h
IDE controller primary channel
278h-27Fh, 378h-37Fh
Parallel port
2E8h-2EFh, 2F8h-2FFh, 3E8h-3EFh, 3F8h-3FFh
Serial port
370h-371h
Integrated I/O Controller
3B0h-3DFh
Integrated video graphics controller
3F0h-3F5h, 3F7h
Integrated flexible disk drive controller
496h-497h
HP reserved
678h-67Bh
Parallel port if ECP mode is selected
778h-77Bh
Parallel port if ECP mode is selected
Refer to the “HP BIOS I/O Port Map” in this chapter for more detailed information.
System Memory Map
00000h - 9FFFFh
640 KB–Base Memory Area
A0000h - BFFFFh
128 KB–Video Memory
C0000h - C7FFFh
32 KB–Video BIOS
C8000h - DFFFFh
96 KB–Accessory Boards Memory
E0000h - E7FFFh
32 KB–Available
E8000h - EFFFFh
Reserved
F0000h - FFFFFh
64 KB–System BIOS
100000h - FFFFFFFFh
1 MB plus–Extended Memory
Reserved memory used by accessory boards must be located in the area from C8000h to
EFFFFh.