_TEXT segment word public use16 'CODE' assume cs:_TEXT, ds:_TEXT, es:nothing org 0100h _entry proc near public mov al, ds:[082h] ; Second character of command line xor ah, ah or ax, 20h ; Force alphas to lower case cmp ax, 's' jnz _reset mov al, 0dh mov dx, _str_tandy jmp _exit _reset: mov al, 7dh mov dx, _str_speaker _exit: out 61h, al mov ah, 09h int 21h ; Display DOS terminated string mov dx, _str_active int 21h ; Display DOS terminated string mov ax, 4c00h int 21h ; Terminate with with return code 0 _entry endp _str_speaker: db "SPEAKER$" _str_tandy: db "TANDY SOUND$" _str_active: db " NOW ACTIVE...$" _TEXT ends end