Category: <b>memory management</b>
<p>
<pre><b>INT 67 - LIM EMS 4.0 - ENABLE/DISABLE OS FUNCTION SET FUNCTIONS</b>

	AH = 5Dh
	AL = subfunction
	    00h enable OS Function Set
	    01h disable OS Function Set
	    02h return access key (resets memory manager, returns access key at
		next invocation)
	BX,CX = access key returned by first invocation
Return: BX,CX = access key, returned only on first invocation of function
	AH = status (see also AH=5Ch)
	    8Fh undefined subfunction
	    A4h operating system denied access
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