INT D4 - PC-MOS/386 v3.0+ - FREE NATIVE MODE MEMORY BLOCK AH = 12h ES = selector for block to free Return: CF clear if successful CF set on error AX = error code (see #01680 at INT 21/AH=59h/BX=0000h) SeeAlso: AH=10h,AH=11h,AH=13h,INT 38