INT 13H 10H: Test Drive Ready

                                                                   [XT] [AT]
 Expects: AH    10H
          DL    drive: 80H-81H=hard disk 0-1
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 Returns: AH    BIOS disk error code if CF is set to CY
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    Info: This determines if the drive specified in DL is ready and can
          process a command.

See Also: INT 13H: BIOS Disk I/O
          BIOS Data Area
          ROM-BIOS Functions
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