55.asm

本书为清华大学第二版汇编语言的课后题详解

;55.asm

codesg  segment
main    proc   far
        assume cs:codesg
start:
        mov ah,01
        int 21h

        sub al,30h
        jl  exit

        cmp al,09
        jg  exit
        cbw
        mov cx,ax

loop1:  mov dl,07
        mov ah,02
        int 21h
        loop loop1

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