)
Call IOS entry point with:
	EAX = function number
	    0000h ???
		Return: CF clear if successful
			    AX = 0000h
			CF set on error
			    AX = FFFFh
	    0001h check if ???
		Return: CF clear if successful
			    AX = 0000h
			CF set on error
			    AX = FFFFh
	    0002h requestor services???
		DL = service number???
		Return: CF clear if successful
			    AX = 0000h
			    DX = ???
			CF set on error
			    AX = FFFFh
		Note:	calls "IOS_Requestor_Service" (see INT 20"Windows")
	    0003h ??? (copies five bytes of data internally)
		Return: CF clear if successful
			    AX = 0000h
			    EDX = ???
			CF set on error
			    AX = FFFFh
	    else
		Return: CF set
			AX = FFFFh
SeeAlso: #02653,#02655