INT 13H 15H: Get Diskette Type or Check Hard Drive Installed

 Expects: AH    15H
          DL    drive: 00H thru 03H = diskette drive
                       80H or 81H   = hard disk
 Returns: AH    00H = not installed
                01H = diskette drive: can't detect disk change
                02H = diskette drive: CAN detect disk change
                03H = it's a hard disk
                else= BIOS disk error code if CF is set to CY
    Info: This checks to see if a hard drive or diskette drive is

          For diskette drives, this also finds if the drive is capable of
          detecting change-line status (that is, will it be able to sense
          when the drive door has been opened).

   Notes: ■ On diskette drives which detect change-line status, you can use
            INT 13H 16H to learn if the disk has been swapped.

See Also: DOS fn 440dH 68H (IOCTL sense media type)
          INT 13H: BIOS Disk I/O
          BIOS Data Area
          ROM-BIOS Functions