)
Call the System 36/38 emulator API entry point with:
	AH = function
	    03h update screen
	    05h select next session
		AL = session number (00h-03h)
		Return: AL = session type code
			    00h not active
			    01h display session
			    02h printer session
			    FEh invalid session number
			DS = requested session's data segment (0 if not active)
			    (see #00008)
Return: ???