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JOY(4)			     Kernel Interfaces Manual			  JOY(4)

NAME
     joy -- joystick device driver

SYNOPSIS
     To link into the kernel:
     device joy

     To load as a kernel loadable module:
	   kldload joy

     #include <sys/joystick.h>

DESCRIPTION
     The joystick device driver allows applications to read the status of the PC
     joystick.

     This device may be opened by only one process at a time.

     The joystick status is read from a structure via a read() call.  The struc-
     ture is defined in the header file as follows:

		   struct joystick {
			   int x;	  /* x position */
			   int y;	  /* y position */
			   int b1;	  /* button 1 status */
			   int b2;	  /* button 2 status */
		   };

     Positions are typically in the range 0-2000.

   One line perl example:
     perl -e 'open(JOY,"/dev/joy0")||die;while(1)
     {sysread(JOY,$x,16);@j=unpack("iiii",$x);print "@j\n";sleep(1);}'

   ioctl calls
     Several  ioctl()  calls  are also available.  They take an argument of type
     int *

     JOY_SETTIMEOUT int *limit
		       Set the time limit (in microseconds) for reading the joy-
		       stick status.  Setting a value too small may  prevent  to
		       get  correct values for the positions (which are then set
		       to -2147483648), however this can be  useful  if  one  is
		       only interested by the buttons status.

     JOY_GETTIMEOUT int *limit
		       Get the time limit (in microseconds) used for reading the
		       joystick status.

     JOY_SET_X_OFFSET int *offset
		       Set the value to be added to the X position  when reading
		       the joystick status.

     JOY_SET_Y_OFFSET int *offset
		       Set the value to be added to the Y position  when reading
		       the joystick status.

     JOY_GET_X_OFFSET int *offset
		       Get  the  value	which  is  added to the X position  when
		       reading the joystick status.

     JOY_GET_Y_OFFSET int *offset
		       Get the value which is added  to  the  Y  position   when
		       reading the joystick status.

TECHNICAL SPECIFICATIONS
     The pinout of the DB-15 connector is as follow:

       1  XY1 (+5v)
       2  Switch 1
       3  X1 (potentiometer #1)
       4  Switch 1 (GND)
       5  Switch 2 (GND)
       6  Y1 (potentiometer #2)
       7  Switch 2
       8  N.C.
       9  XY2 (+5v)
      10  Switch 4
      11  X2 (potentiometer #3)
      12  Switch 3&4 (GND)
      13  Y2 (potentiometer #4)
      14  Switch 3
      15  N.C.

     Pots are normally 0-150k variable resistors (0-100k sometimes), and accord-
     ing  to the IBM techref, the time is given by Time = 24.2e-6s + 0.011e-6s *
     R/Ohms

FILES
     /dev/joy?	joystick device files

AUTHORS
     Jean-Marc Zucconi <jmz@cabri.obs-besancon.fr>

HISTORY
     The joystick driver appeared in FreeBSD 2.0.5.

FreeBSD 4.9			January 23, 1995			  JOY(4)
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