
 Documentation on geographics data stream.

INITIALIZING
   string:  $Ixx           
       xx = hex representation of Xdir + Ydir + Cpi
 Xdir
      increasing to right:    0x00;
                    left:     0x10;
 Ydir
      increasing up:          0x00;
                 down:        0x20;
 Cpi - Coordinates per inch
   Cpi = 1/100:               0x08;
   Cpi = 1/200:               0x04;
   Cpi = 1/400:               0x02;
   Cpi = 1/800:               0x01;

	note: suggested that input buffer be cleared after an initialization
	   e.g. read (IORser, InBuffer, 25);

WRITE KEYPAD
   string:  $Wxx
	 where xx is hex version of numbers 0-9

	note: suggested that input buffer be cleared
	   e.g. read (IORser, InBuffer, 25);

READ ALL DATA
   send string:  $A
   read data:    Actual = read (IORser, InBuffer, 25);
   process data: 
		1) mask all characters to 7 bits   (i.e. char && 0x7f)
		2) Buffer should look like this:
			>A xxxx yyyy ff kk cc
			xxxx:   4 char hex of cur x position
			yyyy:   4 char hex of cur y position
			ff:     footswitch status
			kk:     keyboard status
			cc:     keyboard character

ZERO ORIGIN
   string:  $Z

