Category: <b>DOS extenders</b>
<br>Flags: Undocumented function, available only in protected mode<p>
<pre><b>INT 21 - Rational Systems DOS/4GW - ???</b>

	AH = FFh
	DH = 10h
	AL = ???
	BX = ???
	CX = ???
	DI = ???
	SI = ???
Return: ???
Note:	among other things, frees two memory blocks via INT 21/AH=49h
</pre>