AH = 53h
        AL = subfunction
            00h get handle name
               ES:DI = pointer to 8-byte handle name array
            01h set handle name
               DS:SI = pointer to 8-byte handle name
        DX = handle
Return: AH = status
            00h successful
            80h internal error
            81h hardware malfunction
            83h invalid handle
            84h undefined function requested
            8Fh undefined subfunction
            A1h duplicate handle name
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