*MOUSE (ON/OFF)

*MOUSE enables mouse support routines. Once the mouse is turned on, its
position and button state can be read using OSBYTE or OSWORD. The OSBYTE
routines are accessible using the INKEY and ADVAL calls.

	ADVAL(7)  OSBYTE &80,&07,&00  Mouse X position
	ADVAL(8)  OSBYTE &80,&08,&00  Mouse Y position
	INKEY-10  OSBYTE &81,&F6,&FF  Mouse left button
	INKEY-11  OSBYTE &82,&F5,&FF  Mouse middle button
	INKEY-12  OSBYTE &82,&F4,&FF  Mouse right button

For compatibility, the mouse state can also be read using OSWORD 64, which
returns the following information:

	XY+0,1	Mouse X coord
	XY+2,3	Mouse Y coord
	XY+4	Text X coord (POS)
	XY+5	Text Y coord (VPOS)
	XY+6	button state, %rml00000, 0 - button pressed

INKEY-107, INKEY-108 and INKEY-109 will also return the state of the left,
middle and right buttons.

*MOUSE configures itself for the appropriate wiring for the BBC/Master, the
Electron, or for the Compact. This can be overridden with *MOUSE AMX to use
the AMX wiring or *MOUSE COMPACT, *MOUSE MARCONI or *MOUSE RB5 to use the
Compact wiring, which is also used by the Marconi RB5 trackerball.