APPENDIX
MB900-R 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 that 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
278h - 27Fh
Parallel Port #2(LPT2 )
2F8h - 2FFh
Serial Port #2(COM2)
2B0h - 2DFh
Graphics adapter Controller
378h - 3FFh
Parallel Port #1(LPT1)
360h - 36Fh
Network Ports
3B0h - 3BFh
Monochrome & Printer adapter
3C0h - 3CFh
EGA adapter
3D0h - 3DFh
CGA adapter
3F0h - 3F7h
Floppy Disk Controller
3F8h - 3FFh
Serial Port #1(COM1)