_DATA segment word public 'DATA' _DATA ends _BSS segment word public 'DATA' _BSS ends DGROUP group _DATA, _BSS EXTERNAL_TEXT segment byte public 'CODE' assume cs: EXTERNAL_TEXT, ds: DGROUP public _ADD _ADD proc near push bp mov bp, sp mov ax, 6[bp] add ax, 4[bp] pop bp ret 4 _ADD endp EXTERNAL_TEXT ends end