1.\" $OpenBSD: joy.4,v 1.15 2015/01/15 20:37:36 schwarze Exp $ 2.\" 3.\" Copyright (c) 1996 Matthieu Herrb 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by Christopher G. Demetriou. 17.\" 3. The name of the author may not be used to endorse or promote products 18.\" derived from this software without specific prior written permission 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30.\" 31.\" $NetBSD: joy.4,v 1.2 1996/03/31 00:17:43 perry Exp $ 32.\" 33.Dd $Mdocdate: January 15 2015 $ 34.Dt JOY 4 i386 35.Os 36.Sh NAME 37.Nm joy 38.Nd games adapter 39.Sh SYNOPSIS 40.Cd "joy0 at isa? port 0x201" 41.Cd "joy* at isapnp?" 42.Sh DESCRIPTION 43This driver provides access to the games adapter. 44The lower bit in the minor device number selects the joystick: 0 is the first 45joystick and 1 is the second. 46.Pp 47The game control adapter allows up to two joysticks to be attached to 48the system. 49The adapter plus the driver convert the present resistive value to a relative 50joystick position. 51On receipt of an output signal, four timing circuits are started. 52By determining the time required for the circuit to time-out (a function of 53the resistance), the paddle position can be determined. 54The adapter could be used as a general purpose I/O card with four 55analog (resistive) inputs plus four digital input points. 56.Pp 57Applications may call 58.Fn ioctl 59on a game adapter driver file descriptor 60to set and get the offsets of the two potentiometers and the maximum 61time-out value for the circuit. 62The 63.Fn ioctl 64commands are listed in 65.In machine/joystick.h 66and currently are: 67.Pp 68.Bl -tag -width JOY_GET_X_OFFSET -offset indent -compact 69.It JOY_SETTIMEOUT 70Sets the maximum time-out for the adapter. 71.It JOY_GETTIMEOUT 72Returns the current maximum time-out. 73.It JOY_SET_X_OFFSET 74Sets an offset on X value. 75.It JOY_GET_X_OFFSET 76Returns the current X offset. 77.It JOY_SET_Y_OFFSET 78Sets an offset on Y value. 79.It JOY_GET_Y_OFFSET 80Returns the current Y offset. 81.El 82.Pp 83All of these commands take an integer parameter. 84.Pp 85Read() on the file descriptor returns a 86.Fa joystick 87structure: 88.Bd -literal -offset indent 89struct joystick { 90 int x; 91 int y; 92 int b1; 93 int b2; 94}; 95.Ed 96.Pp 97The fields have the following functions: 98.Pp 99.Bl -tag -width xxx -offset indent -compact 100.It Fa x 101Joystick's current X coordinate (or position of paddle 1). 102.It Fa y 103Joystick's current Y coordinate (or position of paddle 2). 104.It Fa b1 105Current state of button 1. 106.It Fa b2 107Current state of button 2. 108.El 109.Pp 110The 111.Fa b1 112and 113.Fa b2 114fields in struct joystick are set to 1 if the corresponding button is down, 115or 0 otherwise. 116.Pp 117The X and Y coordinates are supposed to be between 0 and 255 for a 118good joystick and a good adapter. 119Unfortunately, because of the hardware hack that is used to measure the 120position (by measuring the time needed to discharge an RC circuit made from 121the joystick's potentiometer and a capacitor on the adapter), calibration 122is needed to determine exactly what values are returned for a specific 123joystick/adapter combination. 124Incorrect hardware can yield negative or > 255 values. 125.Pp 126A typical calibration procedure uses the values returned at lower-left, 127center, and upper-right positions of the joystick to compute the relative 128position. 129.Pp 130This calibration is not part of the driver. 131.Sh FILES 132.Bl -tag -width /dev/joy0 -compact 133.It Pa /dev/joy0 134first joystick 135.It Pa /dev/joy1 136second joystick 137.El 138.Sh SEE ALSO 139.Xr ioctl 2 , 140.Xr intro 4 , 141.Xr isa 4 , 142.Xr isapnp 4 143.Sh AUTHORS 144.An -nosplit 145.An Jean-Marc Zucconi 146wrote the 147.Fx 148driver. 149.An Matthieu Herrb 150ported it to 151.Ox 152and wrote this manual page. 153