Article 7029 of comp.org.decus:
John wrote:
> 
> I am attempting to attach a DEC digitising tablet (VSXXX-AB) to a PC.
> 
> Does anyone have information about the format of data coming from
> the tablet, so far, I can turn it on and off.
> 
> Any help would be much appreciated
> 
> Cheers
> John :-)

  5-bytes

	Byte 1:

		Bit 0		Proximity (0 in, 1 out)
		Bits 1:4	Button 1-4 (0 up, 1 down)
		Bits 5:6	Bit 6 always 1, Bit 5 always 0
		Bit 7		Phasing.  Only set to 1 for byte 1
				Set to zero for all other bytes.
	Byte 2:
		Bits 0:5	x0-x5 low order 6 bits of X
	Byte 3:
		Bits 0:6	x6-x11 high order 6 bits of X
	Byte 4:
		Bits 0:5	y0-y5 low order bits of Y
	Byte 5:
		Bits 0:5	y6-y11 high order bits of Y


  If byte one (bit 7 = 1) has bit 6 = 0, and bit 5 = 1, then it is
  a 4-byte self test report.  Sent at power up, and on request.
  The interesting bits are byte 2, bits 0:4 which will be ^b0100
  for the tablet and ^b0010 for a mouse.

  Commands:

	BREAK		Self test
	B		Change baud rate from 4800 to 9600
	D		Request point mode (data only sent on a
			button press)
	K		Sample rate 55
	L		Sample rate 72
	M		Sample rate 120
	P		Request position report
	R		Request Incremental Stream mode (default)
	T		Request self test



-- 
Frederick G. Kleinsorge       | Standard disclaimer:  All opinions
OpenVMS Engineering           | expressed are mine, and not those of my
Digital Equipment Corporation | employer, or any one else with half a
kleinsorge@star.enet.dec.com  | clue.  No refunds on sale items.