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APPENDIX
MB950 User’s Manual
55
Appendix
A. I/O Port Address Map
Each peripheral device in the system is assigned a set of I/O port
addresses which also becomes the identity of the device. The following
table lists the I/O port addresses used.
Address
Device Description
000h - 01Fh
DMA Controller #1
020h - 03Fh
Interrupt Controller #1
040h - 05Fh
Timer
060h - 06Fh
Keyboard Controller
070h - 07Fh
Real Time Clock, NMI
080h - 09Fh
DMA Page Register
0A0h - 0BFh
Interrupt Controller #2
0C0h - 0DFh
DMA Controller #2
0F0h
Clear Math Coprocessor Busy Signal
0F1h
Reset Math Coprocessor
1F0h - 1F7h
IDE Interface
2E8h - 2FFh
Serial Port #4(COM4)
2F8h - 2FFh
Serial Port #2(COM2)
2B0 - 2DF
Graphics adapter Controller
3C0 - 3CF
EGA adapter
3D0 - 3DF
CGA adapter
3E8h – 3EFh
Serial Port #3(COM3)
3F8h - 3FFh
Serial Port #1(COM1)