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

	AH = FFh
	DH = 00h
	DL = ??? (78h seen)
Return: CF clear
	EAX = 4734FFFFh (high word is byte-swapped "4G") if DOS/4G installed
Note:	Quarterdeck's DESQview/X X Toolkit library uses this call to determine
	  whether the direct-mapped linear 4GB segment's selector is 34h or 38h
SeeAlso: INT 21/AH=FFh/DH=00h"DOS/4GW"
</pre>