)
Call Access Server driver "get port status" function with:
	AH = 02h
	AL = port number (00h-0Fh)
	interrupts disabled
Return: CF clear if successful
	    BL = transmitter status (see #02920)
	    BH = receiver status (see #02921)
	    DL = external status signals (see #02922)
	CF set on error
	interrupts disabled
SeeAlso: #02910,#02912,#02915