BIOS Setup
- 34 -
104-1816CL2NA
IO Port Address
Only 16 IO address lines are designed for X86, from 0 ~ 0FFFFh; there is 64K for the
system I/O address space. In traditional ISA connector, only the foregoing 1024 (0000
~ 03FFh) are adopted while the ports above 0400h are adopted by PCI and EISA
connectors. Each peripheral will occupy portion of the space. The table below shows
the I/O connectors used in X86 platform.
Address
Device Description
020h - 021h
Programmable Interrupt Controller
024h - 025h
Programmable Interrupt Controller
028h - 029h
Programmable Interrupt Controller
02Ch – 02Dh
Programmable Interrupt Controller
02Eh – 02Fh
Motherboard resource
030h - 031h
Programmable Interrupt Controller
034h - 035h
Programmable Interrupt Controller
038h - 039h
Programmable Interrupt Controller
03Ch – 03Dh
Programmable Interrupt Controller
040h - 043h
System Timer
4Eh – 4Fh
Motherboard resource
050h – 053h
System Timer
60h
PS/2 standard keyboard
61h System
speaker
62h-63h
Motherboard resource
65h-6fh Motherboard
resource
070h - 077h
System CMOS/Real Time Clock
80h-8Fh Motherboard
resource