Category: <b>MS Windows</b>
<br>Flags: callout or callback (usually hooked rather than called)<p>
<pre><b>INT 2F - MS Windows - "PageFile" VIRTUAL DEVICE - GET LOCK BYTE</b>

	AX = 1607h
	BX = 0021h (PageFile VxD ID)
	CX = 0000h
Return: AX = status
	    0000h success
		ES:DI -&gt; cache lock byte in disk cacher
	    other no disk cache or unsupported
Notes:	PageFile issues this call on real-mode initialization in order to allow
	  disk caches to provide it with a byte which it can use to temporarily
	  lock the disk cache; VMPOLL also issues this call, so it is made
	  twice each time Windows starts up
	if this call fails, PageFile falls back to other techniques for locking
	  the disk cache
SeeAlso: AX=1607h"CALL OUT API"
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