0605:0728 B80010            mov     ax, 1000
 0605:072B CD2F              int     2F
 0605:072D C3                retn

 !-u 2E98
 0605:2E98 803EB20C00        cmp     byte [0CB2], 00
 0605:2E9D 750C              jnz     2EAB
 0605:2E9F E886D8            call    0728
 0605:2EA2 3CFF              cmp     al, FF
 0605:2EA4 7505              jnz     2EAB
 0605:2EA6 C606B20C01        mov     byte [0CB2], 01
 0605:2EAB A0B20C            mov     al, [0CB2]
 0605:2EAE 98                cbw
 0605:2EAF C3                retn