Int D4 Fn 12  - Pc-mos/386 V3.0+ - Free Native Mode Memory Block           [O]

   AH = 12h
   ES = selector for block to free

Return: CF clear if successful
   CF set on error
       AX = error code (see #1366 at INT 21/AH=59h/BX=0000h)

See Also: AH=10h,AH=11h,AH=13h,INT 38