XMS 0aH: Free Extended Memory Block

                                                     Compatibility: XMS 2.0+ 
 Expects: AH    0aH
          DX    XMS handle (as obtained via XMS 09H)
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 Returns: AX    status: 0000H = successful
                        0001H = error and BL=XMS error code (if BL >= 80H)
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    Info: This fn frees a block of extended memory that was previously
          allocated via XMS 09H (allocate XMB).

          When an XMB is freed, its handle and all data in it become
          invalid and should not be accessed.

See Also: XMS Functions
          Extended Memory Specification (XMS)
          DOS Functions
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