Int 21 Fn 3E  - Dos 2+ - "close" - Close File                              [D]

   AH = 3Eh
   BX = file handle

Return: CF clear if successful
       AX destroyed
   CF set on error
       AX = error code (06h) (see #1366 at AH=59h/BX=0000h)

Notes: if the file was written to, any pending disk writes are performed, the
     time and date stamps are set to the current time, and the directory
     entry is updated
   recent versions of DOS preserve AH because some versions of Multiplan
     had a bug which depended on AH being preserved

See Also: AH=10h,AH=3Ch,AH=3Dh,INT 2F/AX=1106h,INT 2F/AX=1227h