59.asm

汇编语言课后习题答案

;59.asm

codesg  segment
main    proc   far
        assume  cs:codesg
start:
        mov  bx,0
        mov  cx,4
newchar:mov  ah,01
        int  21h

        cmp  al,30h
        jl   exit

        cmp  al,39h
        jg   next1

        sub  al,30h
        jmp  short next2

next1:  cmp  al,41h
        jl   exit

        cmp  al,46h
        jg   exit

        sub  al,30h
        sub  al,07h

next2:  cbw
        xchg ax,bx
        mov  si,10h
        mul  si
        xchg ax,bx
        add  bx,ax
        loop newchar

        mov  dl,0dh
        mov  ah,02
        int  21h

        mov  dl,0ah
        mov  ah,02
        int  21h

        mov  cx,16
loop2:  shl  bx,1
        jc   next3

        mov  dl,30h
        mov  ah,02
        int  21h

        jmp  short next4

next3:  mov  dl,31h
        mov  ah,02
        int  21h

next4:  loop loop2

        mov  dl,0dh
        mov  ah,02
        int  21h

        mov  dl,0ah
        mov  ah,02
        int  21h

        jmp  near ptr start

exit:   mov  ax,4c00h
        int  21h
main    endp
codesg  ends
        end  start