  The Linux Busmouse Howto
  Chris Bagwell, cbagwell@sprynet.com
  v1.07, 1 February 1998

  1.  Introduction.

  This document is a guide to getting your busmouse working with Linux.
  During early kernel versions it was quite common to see questions come
  up about how to get bus mice working under Linux.  With the more
  advanced distributions available today the questions do not seem to
  come up as often but there still seems to be an audience for this FAQ.

  Busmouse support has been in the kernel for as long as I can remember,
  and hasn't changed much in a long time, so this document should be
  relevant to any version of Linux you're likely to have.

  1.1.  Disclaimer.

  The information in this document is correct to the best of my
  knowledge, but there's a always a chance I've made some mistakes, so
  don't follow everything too blindly, especially if it seems wrong.
  Nothing here should have a detrimental effect on your computer, but
  just in case I take no responsibility for any damages incurred from
  the use of the information contained herein.

  Microsoft(R) is a Trademark of Microsoft Corporation.

  [ trademark notices for other mice, anyone? ]

  1.2.  Feedback.

  If you find any mistakes in this document, have any comments about its
  contents or an update or addition, send them to me at the address
  listed at the top of this howto.

  1.3.  Acknowledgements.

  This howto has been, in the spirit of Linux, a community effort.
  Thanks goes out to Mike Battersby, mib@deakin.edu.au as he started
  this FAQ and I have since started up-keep on it.  Any errors are most
  likely mine.

  Many thanks go to Johan Myreen for the sections on the PS/2 mice,
  Robert T. Harris for help on the ATI-XL sections and Reuben Sumner for
  miscellaneous info and constructive criticism.

  Thanks also to the multitudes of people who have sent me mouse
  information, fixes or words of encouragement.

  2.  Determining your mouse type.

  There are two separate but important characteristics you will need to
  know about your mouse before you go on: what mouse interface it uses
  and what mouse protocol it uses.  The interface is the hardware aspect
  of the mouse, taking into account things like which i/o ports it uses
  and how to check if it is installed.  This is the part which the
  kernel is concerned with, so that it knows how to read data from the
  mouse.  The protocol is the software aspect of the mouse.
  Applications need to know the protocol to interpret the raw mouse data
  they receive from the kernel.

  2.1.  Mouse interfaces.

  The Linux kernel currently supports four different kinds of bus mouse
  interface : Inport (Microsoft), Logitech, PS/2 and ATI-XL.  There is
  no sure-fire way of determining your mouse interface --- mouse
  developers generally do their own thing when it comes to standards.
  The following sections may help, otherwise you'll just have to make it
  up.

  2.2.  Inport mice.

  This includes most of the old style Microsoft mice which are shaped
  like a bar of dove soap.  U.S. users who have purchased Gateway
  computers should note that the mice that come with them are not Inport
  mice but PS/2 mice (see below).  Inport mice generally connect to an
  interface card which plugs into the bus on your motherboard.  If the
  plug which connects your mouse cord to the interface card is round,
  has 9 pins, and a notch in one side you likely have an Inport mouse.

  As far as I can tell, apart from the ATI-XL, all ATI mice (such as
  those on the Graphics Ultra cards) are plain Inport mice.

  2.3.  Logitech mice.

  Logitech mice in general appear almost exactly the same as Inport
  mice.  They too connect to an interface card via a 9 pin mini-din
  connector.  Hopefully, it will have come in a Logitech box or have
  ``Logitech'' printed on the connector card so that you can tell it
  actually is a Logitech mouse.

  There are also some truly ancient Microsoft mice (ones with ball
  bearings on the bottom as well as the mouse ball and a DB9 connector)
  which also use the Logitech protocol.

  2.4.  PS/2 mice.

  PS/2 mice aren't really bus mice at all.  The PS/2 mouse interface is
  not on an expansion card, the mouse is connected to the PS/2 Auxiliary
  Device port on the keyboard controller.  A PS/2 mouse port uses a
  6-pin mini DIN connector, similar to the keyboard connector.  Many
  laptops also use this kind of interface to their trackballs --- except
  for the connector, of course.

  2.5.  ATI-XL mice.

  ATI-XL mice are a variant of Inport mice, with some slight
  differences.  They come on the ATI-XL combined video adaptor/mouse
  card.  Unless you know you have an ATI-XL card (and thus an ATI-XL
  mouse), you probably don't have one of these. It is possible for ATI-
  XL mice to use either the ATI-XL or Inport kernel drivers, although
  the ATI-XL driver should give better results.

  2.6.  Mouse protocols.

  The PC world is full of different and conflicting mouse protocols.
  Fortunately, the choice for bus mice is considerable smaller than that
  for serial mice.  Most Inport, Logitech and ATI-XL mice use the
  ``BusMouse'' protocol, although there are some ancient Logitech mice
  which use the ``MouseSystems'' protocol, and some even older Microsoft
  mice which use the ''Logitech'' protocol.  PS/2 mice use the ``PS/2''
  protocol.

  3.  Getting your mouse working.

  Once you have figured out your mouse interface and protocol types,
  you're ready to proceed.

  3.1.  Setting the mouse interrupt.

  Now, you'll need to know which interrupt number your mouse is using,
  and make sure it doesn't conflict with any other peripherals you have
  installed.

  You should make sure that your mouse is not trying to use the same
  interrupt as any of your other devices --- it is not possible for the
  mouse to share an interrupt under Linux, even though it may work fine
  under other operating systems.  Check the documentation for all your
  peripherals to see which interrupt they use.  In most cases IRQ4 is
  used for the first serial port (/dev/ttyS0), IRQ3 for the second
  (/dev/ttyS1) (these are assuming you actually have such devices --- if
  you don't you can happily use their IRQ's), and IRQ5 for some SCSI
  adaptors.

  Note that for ATI-XL, Inport and Logitech mice the kernel default is
  to use IRQ5, so if you are stuck with a pre-compiled kernel (eg, CD-
  ROM users) you will have to use that.  If you are using an Inport or
  Logitech mice with a newer kernel you may be able to pass a command
  line option to the kernel to tell it what interrupt to use without
  recompiling.

  3.2.  Inport and Logitech mice.

  If you open up your computer's case and look at the card which your
  mouse plugs into, you should notice a block of jumpers on the card
  (hopefully labeled ``INTERRUPT'') with positions for interrupt
  (otherwise known as IRQ) numbers 2,3,4 and 5.  To change the interrupt
  simply move the jumper from its current position onto the correct pair
  of pins.

       ***************************************************
       ***     MAKE SURE YOUR COMPUTER IS TURNED OFF   ***
       ***     BEFORE CHANGING THE JUMPERS AROUND.     ***
       ***************************************************

  3.3.  ATI-XL mice.

  ATI-XL busmice have a software selectable IRQ - you should have
  received with your mouse a MS-DOS program (VSETUP.EXE) to set the IRQ.
  In order to do so you must (temporarily) boot MS-DOS and run this
  program.  Note that the VSETUP program takes an optional parameter
  ``/70'' to increase the vertical refresh rate (which results in less
  flicker).  The VSETUP program also allows you to select either the
  primary or secondary mouse address - you should set this to the
  primary address or the kernel will not be able to detect your mouse.

  Once VSETUP has been run you must perform a hard reset for the new
  configuration to take effect.

  3.4.  PS/2 mice.

  The PS/2 mouse always uses IRQ12 -- there is no way of changing this
  (except with a soldering gun.)  In the rare case that some other
  device is using IRQ12, you'll have to rejumper that peripheral to use
  another IRQ number.

  3.5.  Configuring the kernel.

  In order for your busmouse to operate correctly you will need to
  configure your kernel to compile in busmouse support.  If you are
  using a pre-compiled kernel then it often comes with support for all
  three busmouse included.  This may still not be enough.  The kernel
  could be trying to use the wrong interrupt or the detection can get
  confused and treat your mouse as the wrong type.  When in doubt, try
  recompiling your kernel with only support for your mouse type and set
  it to use the correct interrupt.

  3.5.1.  Compiling the kernel.

  Change to your kernel directory (here assumed to be (/usr/src/linux)
  and do a

       make config

  If you are unsure as to your mouse type, the first time you recompile
  the kernel you may wish to enable all of the busmouse options in the
  hope that the kernel will autodetect your mouse properly.  People have
  mixed success with this: it doesn't always work, but on the other hand
  it might save you any further compiles.

  Answer ``y'' or ''m'' to the question pertaining to your type of
  busmouse interface and ``n'' to all the other busmouse questions.  Use
  the ''m'' option if you have your system setup to support loading
  kernel modules if you do not or do not know what that means then it
  will be safe to always answer ''y'' to have the support directly
  compiled into your kernel.

  As an example, if you have an Inport mouse you should answer ``y'' to

       Microsoft busmouse support

  and ``n'' to all other busmouse questions.  Answer the non-mouse
  related questions as you usually would.

  To compile the kernel with PS/2 mouse support answer ``y'' to the
  question.

       PS/2 mouse (aka "auxiliary device") support

  The PS/2 mouse driver actually supports two kinds of devices: the
  standard PS/2 Auxiliary Device controller and a special PS/2 mouse
  interface chip from Chips & Technologies which is used in the Texas
  Instruments Travelmate and Gateway Nomad laptops.  To compile in
  support for the trackballs on these computers, answer ``y'' to the

       C&T 82C710 mouse port support (as on TI Travelmate)

  question.  Note that you will still have to answer ``y'' to the ques­
  tion about the standard PS/2 driver to even get a chance to answer
  this question, since the 82C710 driver is actually an add-on to the
  standard PS/2 mouse driver.

  When configured both for a standard PS/2 mouse device and the 82C710
  device, the driver first tries to locate a 82C710 chip at boot time.
  Failing this, the standard driver is used instead, so using a kernel
  configured for both types of interface on a machine with a standard
  PS/2 mouse port should work too.  However, there has been one report
  of a falsely detected 82C710 chip, so to be on the safe side do not
  configure in support for the 82C710 if you don't need it.

  You will now need to tell the kernel what interrupt your mouse uses.
  You can skip this step if your using a PS/2 mouse as it always uses
  IRQ 12.

  If you have a Logitech or Inport mouse, edit the file
  /usr/src/linux/include/linux/busmouse.h and change the line which says

       #define MOUSE_IRQ               5

  to reflect the interrupt number for your mouse (see the section ``Set­
  ting the mouse interrupt'' for details on finding your interrupt num­
  ber).

  If you have an ATI-XL mouse, edit the file
  /usr/src/linux/drivers/char/atixlmouse.c and change the line which
  says

       #define ATIXL_MOUSE_IRQ         5

  to reflect your mouse's interrupt number.

  Due to the vagaries of the PC architecture, if you have set your mouse
  to use interrupt 2, you must set the #define to use interrupt 9.

  Examples

  For a mouse on interrupt 3, you should change the line to read

  #define MOUSE_IRQ               3

  For a mouse on interrupt 2, you should change the line to read

       #define MOUSE_IRQ               9

  Next, compile your kernel as per the instructions which come with it,
  and boot from the new kernel.  You should now have the busmouse
  support correctly compiled in.

  3.5.2.  selection.

  It appears that in older kernels you had to compile in support to use
  the program selection (a program that allows you to cut and past from
  virtual consoles the same way you do under X).  This option does not
  appear in modern kernels and the program selection has generally been
  replaced with the program gpm (see the section ``gpm'' for more
  details).

  If you are working with an old kernel then you may wish to set this
  option to ``y'' regardless of your mouse type so that you may use the
  selection program.

  3.5.3.  Changing interrupts with newer kernels.

  The steps to compile into the kernel what interrupt it uses works with
  any version of the kernel to date.  Newer kernels (starting somewhere
  in  the 2.x.x's) allow you to pass arguments to the kernel during load
  time using something like LILO or LOADLIN to specify the interrupt
  number for Logitech and Microsoft Inport mice.  This can be a real
  time saver as you do not need to recompiler your kernel (or know how
  to).  If you've configured your kernel to load the mouse drivers as
  modules then you will need to pass this information when loading the
  module.

  You can add the following options to your boot line in LILO to change
  interrupt:

       bmouse=3  (Logitech Busmice)
       msmouse=3 (for Microsoft Inport mice)

  Substitute the 3 with your mouse's actual interrupt. An example of
  using this with lilo is:

       LILO:linux msmouse=3

  You can consult your LILO or LOADLIN docs to see how to add this type
  information to their configuration files so that you do not need to
  type it.
  When using modules you can manually set the interrupt by using insmod
  as follows:

       insmod msbusmouse.o mouse_irq=3    (use for Inport mice)
       insmod busmouse.o mouse_irq=3      (use for Logitech mice)

  If your system uses kerneld to auto load modules, you can edit your
  /etc/conf.modules or /etc/modules.conf file, which ever your system
  uses, and add one of the following lines.

       options msbusmouse mouse_irq=3
       options busmouse mouse_irq=3

  3.6.  The mouse devices.

  Mice under Linux are accessed via the devices in the /dev directory.
  The following table gives a list of interface types and which device
  you should use.

       INTERFACE        DEVICE        MAJOR    MINOR
       ---------------------------------------------
       Logitech        /dev/logibm      10      0
       PS/2            /dev/psaux       10      1
       Inport          /dev/inportbm    10      2
       ATI-XL          /dev/atibm       10      3

           Table 1.  Mouse devices.

     Note:
        If you are using your ATI-XL mouse with the Inport driver, you
        should use the inportbm device, not the /dev/atibm device.

  The major and minor entries are the device numbers for that particular
  device.

  If you find that you do not have these devices, you should create them
  first.  To do so, execute the following as root.

       mknod /dev/logimm    c 10 0
       mknod /dev/psaux     c 10 1
       mknod /dev/inportbm  c 10 2
       mknod /dev/atibm     c 10 3

     Note:
        Some time in the (progressively less) recent history of Linux
        the names for the busmouse devices have changed.  The following
        device names have been superceded by those above and should be
        removed: bmousems, bmouseps2, bmouseatixl, and bmouselogitech..

  Many people like to create a symbolic link from their mouse device to
  /dev/mouse so that they don't have to remember which device they need
  to be using.  If you have one of the current Linux distributions you
  will almost certainly find that you have such a link.  If you have
  such a link, or create one, you should make sure that it is pointing
  to the correct device for your mouse.

  4.  Using your mouse.

  4.1.  gpm.

  Gpm is a program which allows you to do mouse based 'cut- and-paste'
  between Linux virtual consoles, much like you can under X, and is a
  good way of testing your mouse out. The current version of gpm is
  gpm-1.13.tar.gz
  <http://sunsite.unc.edu/pub/Linux/system/mouse/gpm-1.13.tar.gz> and
  can be found at your friendly Linux FTP site (such as
  sunsite.unc.edu), and contains instructions for getting it compiled.
  Some Linux distributions, such as Red Hat, come with a precompiled gpm
  binary.

  When invoking gpm, use the -t switch to indicate which protocol your
  mouse is using and the -m option to indicate which mouse device you
  are using.  Three protocols useful for most busmice are logi, bm, and
  ps2.  The default for mouse device is to use /dev/mouse, so you can
  omit the -m option if you have the appropriate symbolic link.  An
  example for a Microsoft Inport mouse is:

       gpm -t bm

  or if you use the PS/2 protocol:

       gpm -t ps2

  You should then be able move your mouse and see a block move around
  the screen and also be able to cut and paste text between virtual
  consoles using the mouse buttons.  Read the documentation with gpm, or
  do a ``man gpm'' for more information on how to operate it.

  4.2.  XFree86.

  To use your busmouse under XFree86, you will need to set your mouse
  protocol type in your Xconfig file. If you have a BusMouse protocol
  mouse, your Xconfig should contain (including the quotes)

  Section "Pointer"
    Protocol "Busmouse"
    Device   "/dev/mouse"

    # Any other options such as Emulate3Buttons
  EndSection

  For PS/2 mice change the protocol line to:

         Protocol        "PS/2"

  If you have a two button mouse, it should also contain the line

         Emulate3Buttons

  which will allow you to emulate the use of the middle mouse button by
  pressing both mouse buttons simultaneously.  All other mouse related
  lines, such as ``BaudRate'' and ``SampleRate'' should be commented
  out, as these have no effect on bus mice.

  4.3.  XFree86 and gpm.

  For a long period of the kernel developement, it was not possible to
  share busmice between processes.  Because of this it was hard to run
  both XFree86 and gpm at the same time. If you try to run X with gpm
  running and you get errors like the following then you know you are
  using one of these older kernels.

       Fatal server error:
       Cannot open mouse (Device or resource busy)

  There are two meathods of getting gpm working with XFree86 with these
  kernels.  The first is to kill any copy of gpm you have running before
  you start up XFree86.  The second is to use gpm's "repeater" option
  (it takes mouse data and repeats the information to multiple
  applications).

  I would recommend upgrading your kernel if possible so that you can
  share busmice between processes.  For this document, I will only
  explain the simplest meathod of using XFree86 and gpm together with
  older kernels.  Please see gpm's documentation if you would like to
  use the repeater meathod.

  Gpm allows you to terminate running copies of itself by executing:

  gpm -k

  This should be done before starting up X11.  Take whatever script you
  use to start up your X session, such as startx, and add the above com­
  mand to the top of the script so that gpm is shut down automatically.
  You may wish to also put a command that restarts gpm at the bottom of
  the script so that it restarts upon exiting your X session.

  5.  Still can't get your mouse going?

  So you've read through this howto a dozen times, done everything
  exactly as you think you should have, and your mouse still doesn't
  work?  The best advice I can give you is this: experiment.  Sure, it's
  a pain in the posterior, but in the end the only way to find out what
  is going to work with your mouse is to try all of the alternatives
  until you have success.

  As always, if there is something you don't understand, try reading the
  manual page first and see if that helps.  If you have a specific
  question, or a problem you think I might be able to help with, feel
  free to contact me at the address listed at the top of this howto, and
  I'll see if I can help you out or point you to someone who can.

  The comp.os.linux.setup newsgroup or comp.os.linux.hardware is the
  appropriate forum for discussion and/or questions regarding setup ---
  please don't post questions to other groups, and especially don't
  crosspost questions to two or more of the Linux groups, they are more
  than cluttered enough as it is!  When posting, you will get a much
  better response (and much fewer flames) if you use appropriate
  Subject: and Keywords: lines.  For example:

       Subject: BUSMICE - Gateway 2000 mouse wont work.
       Keywords: mouse busmouse gateway

