====== 0 ======

===== Brief =====

===== Input =====

  * BX = file handle

===== Return =====

  * CF clear if successful
    * AX = new handle
  * CF set on error
    * AX = error code (04h,06h) (too many open files (no handles available), invalid handle)

===== Notes =====

moving file pointer for either handle will also move it for the other, because both will refer to the same system file table

===== See also =====