fd_sense_int
if (fd_sense_int(fdc, &st0, &cyl)
(void)fd_sense_int(fdc, &st0, &cyl);
if (fd_sense_int(fdc, &st0, &cyl) == FD_NOT_VALID)
if (fd_sense_int(fdc, &st0, &cyl) != 0)
fd_sense_int(fdc, 0, 0); /* make ctrlr happy */
fd_sense_int(fdc, 0, 0);
if (fd_sense_int(fdc, &st0, 0) == 0 &&