8279 键盘显示实验

实验三   8279键盘显示实验
Z8279    EQU       212H   ;8279状态/命令口地址
D8279    EQU       210H   ;8279数据口地址
LEDMOD   EQU       00h   ;左边输入,八位显示外部译码八位显示；外部译码键扫描方式，双键互锁
LEDFEQ   EQU       38H ;扫描频率
CODE     SEGMENT
ASSUME    CS:CODE,DS:CODE
START:                         ;初始化
     PUSH   CS
     OUT       DX,AL
     POP    DS
     MOV       DX,Z8279
     MOV       AL,LEDMOD
     OUT       DX,AL
     MOV       AL,LEDFEQ
     OUT       DX,AL
     MOV       DX,D8279
     MOV       AL,7FH
     OUT       DX,AL
     MOV       DX,D8279  
     MOV       AL,7FH
     OUT       DX,AL
     MOV       DX,D8279  
     MOV       AL,7DH
     OUT       DX,AL
     MOV       DX,D8279
     MOV       AL,7FH
     OUT       DX,AL
     
 MOV       DX,D8279