Function 1Ah (26)        Set Disk Transfer Address (DTA)

    Sets the Disk Transfer Address (DTA).

       On entry:      AH         1Ah
                      DS:DX      Address of DTA

       Returns:       Nothing

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       Notes:         DOS supplies a default DTA of 128 bytes at offset
                      80h in the Program Segment Prefix (PSP).

                      Reserve sufficient buffer area; DOS will detect and
                      abort disk transfers that would wrap around within
                      the segment or fall off the end of the current
                      segment.

                      This function is used with the FCB Read and FCB
                      Write file operations. It is also used with the
                      "Find First" and "Find Next" functions, both Handle
                      and FCB.