4-9
Serial Port 2 1 2
Auto
1COM1 COM3
2COM2 COM4 Off
Auto
IRQ
•COM3 IRQ4 COM1 /I/O 3F8h COM3 /
I/O 3E8h
•COM4 IRQ3 COM2 / I/O 3F8h COM4
/I/O 3E8h
378h 278h 3BCh
Off
AT PS/2
Parallel Mode
Auto
2COM IRQ
2COM3 COM4
ECP extended capabilities port 278h