8255端口地址：
控制寄存器地址28BH
A口的地址288H
B口的地址289H
C口的地址28AH
实验程序：
DATA SEGMENT
BUF1 EQU 00100100B ;南北绿灯亮东西红灯亮BUF2 EQU 01000100B ;南北黄灯亮东西红灯亮BUF3 EQU 00000100B ;南北灯灭东西红灯亮BUF4 EQU 10000001B ;南北红灯亮东西绿灯亮BUF5 EQU 10000010B ;南北红灯亮东西黄灯亮BUF6 EQU 10000000B ;南北红灯亮东西灯灭DATA ENDS
CODE SEGMENT
ASSUME CS:CODE, DS:DATA
START: MOV AX,DATA
MOV DS,AX
MOV AL,80H
MOV DX,28BH
OUT AX,AL
ALL: MOV AL,BUF1
MOV DX,28AH
OUT DX,AL
CALL DELAYL
MOV CX,5
YEL1: MOV AL,BUF2
MOV DX,28AH
OUT DX,AL
CALL DELAYS
MOV AL,BUF3
MOV DX,28AH
OUT DX,AL
CALL DELAYS
LOOP YEL1
MOV AL,BUF4
MOV DX,28AH
OUT DX,AL
CALL DELAYL
MOV CX,4
YEL21: MOV AL,BUF5
MOV DX,28AH
OUT DX,AL
CALL DELAYS
MOV AL,BUF6
MOV DX,28AH
OUT DX,AL
CALL DELAYS
LOOP YEL2
JMP ALL
MOV AH,4CH
INT 21H
DELAYL PROC NEAR ;长延时
PUSH CX
PUSH DI
Y1：MOV CX,2000H
X1：MOV DI,2000H
DEC DI
JNE X1
LOOP Y1
POP DI
POP CX
RET
DELAYL ENDP
DELAYS PROC NEAR ;短延时
PUSH CX
PUSH DI
Y2：MOV CX,500H
X2：MOV DI,1000H
DEC DI
JNE X2
LOOP Y2
POP DI
POP CX
RET
DELAYS ENDP
CODE ENDS
END START
桂林电子科技大学信息与通信学院。