求汇编实现三位十进制的加法

mov ch, 4

rotate: mov cl, 4

rol bx, cl

mov al, bl

and al, 0fh

add al, 30h

cmp al, 3ah

jl printit

add al, 7h

printit:

mov dl, al

mov ah, 2

int 21h

dec ch

jnz rotate

ret

binihex endp

;-----------------------------------------------------------------------

decibin proc near

mov bx,0

newchar:

mov ah,1

int 21h

sub al,30h

jl exit

cmp al,9d

jg exit

cbw

xchg ax,bx

mov cx,10d

mul cx

xchg ax,bx

add bx,ax

jmp newchar

exit:

ret

decibin endp

;-----------------------------------------------------------------------

crlf proc near

mov dl,0dh

mov ah,2

int 21h

mov dl,0ah

mov ah,2