Category: <b>shells/command interpreters</b>
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<pre><b>INT 2F - 4DOS.COM v2.1+ - API</b>

	AX = D44Dh
	BH = function
	    00h installation check
		Return: AX = 44DDh
			BL = major version number
			BH = minor version number
			CX = PSP segment address for current invocation
			DL = 4DOS shell number (0 for the first (root) shell,
			      updated each time a new copy is loaded)
	    01h (internal, v2.1-3.03) terminate current copy of 4DOS
		Return: nothing
		(internal, v4.0+) ???
		Return: AX = 44DDh
			ES:BX -&gt; data area (see <a href=../../it/86/30.html>#03086</a>)
	    02h ???
		DX = ???
		Note:	v5.52 signals "unrecoverable error" and then terminates
			  with INT 21/AH=4Ch or enters a deliberate infinite
			  loop if ???
	---v2.1-3.03 only---
	    03h EXEC program
		CX:DX -&gt; EXEC record (see <a href=../../it/87/30.html>#03087</a>)
	    FEh deallocate shell number (passed through to root shell)
		???
	    FFh allocate shell number (passed through to root shell)
	---v5.52---
	    03h get ???
		BL = ??? (00h/01h)
		Return: DX = current value of ???
	    04h set ???
		BL = ??? (00h/01h)
		DX = new value for ???
Note:	a bug in v3.00 will crash the system if unrecognized value in BH
SeeAlso: AX=D44Eh,AX=D44Fh/BX=0000h,AX=E44Dh,INT 21/AX=4403h"DOS"
SeeAlso: INT 14/AX=7000h
Index:	installation check;4DOS|installation check;NDOS

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