assembly language, displaying numbers in 10-binary fashion

printit proc near        test ax,8000h    JZ p    neg ax        mov cx,ax    mov dx,2dh    mov ah,2    int  21h    mov ax,cx    mov dx,0p:    mov bx,ten     Div bx    mov bx,dx    mov dx,ax    add dx,30h    mov ah,02h    int  21h    mov dx,bx    add dx,30h    mov ah,02h    int  21h    retprintit ENDP

DIV CX this directive, which is the 32bit value of the Dx:ax combined with the 16bit value of CX, the result of division must be expressed in 16bit, so it can be concluded that if the value of DX is larger than CX before this instruction is executed, it will overflow regardless of whether CX is 0. I guess your intention is to do ax divided by CX, so as long as the first DX cleared 0 on the line.

assembly language, displaying numbers in 10-binary fashion