1开数码管.txt

汇编程序

code segment public
assume cs:code
org 100h
start:
    mov dx,04a0h
    in al,dx
    and al,0f0h
    cmp al,00h
    jz case0
    cmp al,80h
    jz case1
    cmp al,40h
    jz case2
    cmp al,0c0h
    jz case3
    cmp al,20h
    jz case4
    cmp al,0a0h
    jz case5
    cmp al,60h
    jz case6
    cmp al,0e0h
    jz case7
    cmp al,10h
    jz case8
    cmp al,90h
    jz case9
    cmp al,50h
    jz casea
    cmp al,0d0h
    jz caseb
    cmp al,30h
    jz casec
    cmp al,0b0h
    jz cased
    cmp al,70h
    jz casee
    cmp al,0f0h
    jz casef

case0:
    mov al,3fh
    jmp output
case1:
    mov al,06h
    jmp output
case2:
    mov al,5bh
    jmp output
case3:
    mov al,4fh
    jmp output
case4:
    mov al,66h
    jmp output
case5:
    mov al,6dh
    jmp output
case6:
    mov al,7dh
    jmp output
case7:
    mov al,07h
    jmp output
case8:
    mov al,7fh
    jmp output
case9:
    mov al,6fh
    jmp output
casea:
    mov al,77h
    jmp output
caseb:
    mov al,7ch
    jmp output
casec:
    mov al,39h
    jmp output
cased:
    mov al,5eh
    jmp output
casee:
    mov al,79h
    jmp output
casef:
    mov al,71h
    jmp output


output:
    mov dx,04b0h
    out dx,al
    jmp start
    code ends
end start