data segment   ;数据代码段
    buf    db    20,?,20 dup(?)
    A    dw    0
    B    dw    0
    result    dw    ?
    crlf    db 0ah,0dh,'$'
data ends      ;数据代码段结束
code segment   
    assume cs:code,ds:data
start:
    mov ax,data   
    mov ds,ax     
    
    lea dx,buf    
    mov ah,10     
    int 21h       
    inc dx        
    mov di,dx     
    mov cx,[di]   
    and cx,0ffh   
    mov bl,16     
next:
    inc di          
    mov al,[di]   
    cmp al,'+'    
    je    jadd      
    cmp al,'-'    
    je    jsub
    
    cmp al,'Z'
    jle no1       
    sub al,20h
no1:
    cmp al,'9'
    jle no2
    sub al,7
no2:
    sub    al,30h    
    mov bh,al
    mov ax,A
    mul bl        
    mov A,ax
    mov al,bh
    and ax,0ffh   
    add A,ax
    dec cx        
    jmp next      
jadd:
    call proc1    
    mov ax,A
    add ax,B
    jmp exit
jsub:
    call proc1
    mov ax,A
    sub ax,B
    jmp exit
exit:
    mov result,ax
    lea dx,crlf
    mov ah,9
    int 21h
    lea bx,buf
    mov ax,[bx+1]
    and ax,0ffh
    add bx,ax
    mov byte ptr[bx+2],'='   
    mov byte ptr[bx+3],'$'  
    lea dx,buf
    add dx,2
    mov ah,9       
    int 21h
    mov ax,result 
    call DISPLAY    
    mov ah,4ch
    int 21h            
proc1    proc    near
        mov bl,16
        dec cx      
continue:
        inc di    
        mov al,[di]
        cmp al,'Z'    
        jle no5       
        sub al,20h   
no5:
        cmp al,'9'    
        jle no6       
        sub al,7
no6:
        sub    al,30h
        mov bh,al
        mov ax,B
        mul bl       
        mov B,ax
        mov al,bh
        and ax,0ffh   
        add B,ax
        loop continue 
    ret
proc1    endp
DISPLAY    PROC    NEAR   
    MOV CX,0    
    MOV    BX,16
CONTINUE1:
    XOR DX,DX     
    DIV    BX
    PUSH DX       
    INC    CX
    CMP    AX,0
    JNZ    CONTINUE1   
    
NEXT1:
    POP DX         
    AND DX,0FFH
    ADD DL,30H
    CMP DL,'Z'
    JLE no3
    SUB DL,20H     
no3:    
    CMP DL,'9'
    JLE no4
    ADD DL,7
no4:
    MOV AH,02
    INT 21H
    LOOP NEXT1       
    mov ah,01h
    int 21h
DISPLAY    ENDP
code ends       
    end    start

这个代码是我从网上找来的一段代码，但是测试之后发现有点小问题
这个代码实现的是简易计算器功能
但是当测试1111+1111时显示的是222
貌似少了一位
但是我也不知道问题出在哪里
（我只留下了程序中的加法和减法运算）
求解~