Category: <b>keyboard enhancers</b>
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<pre><b>INT 2F - 4DOS v4.0+ - KSTACK.COM - INSTALLATION CHECK</b>

	AX = D44Fh
	BX = 0000h
Return: AX = 44DDh if installed
Note:	this function is also supported by ANSIPLUS v3.01+ and K3PLUS v6.20+,
	  which emulate the 4DOS and NDOS keystack
SeeAlso: AX=D44Dh,AX=D44Fh/BX=0001h,AX=E44Fh/BX=0000h
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