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Making Mouse Wheels Work w/ a KVM? 85

Elvii asks: "My mouse wheel doesn't want to work through my KVM. It doesn't work in X11 under Linux (Debian 3.0, kernel 2.4.20), but it works in Windows on same machine, through same KVM, so that tells me it's a protocol or driver issue , which is beyond me. I have no other OS's to test on, although I read online that FreeBSD can handle the mouse wheel in this type of setup. When I set the mouse type to IMPS/2, it just twitches in corner and randomly clicks. Anyone know if it's a kernel issue or an X11 issue? I've googled and found nothing of real use there - just that some KVMs work and some don't. Plain PS/2 works but I want my wheel too." The kicker is that when the mouse is plugged directly to the machine, the mouse wheel works just fine! Has anyone else experienced the problem? What did you do to fix it?
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Making Mouse Wheels Work w/ a KVM?

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  • USB (Score:2, Informative)

    by DeadSea ( 69598 ) *
    USB has allowed me to give up an expensive KVM. All the computers in my rack now have a couple USB ports.
    1. Get a USB keyboard with a built in hub (~$50)
    2. Get a USB mouse with a scroll wheel (~$30)
    3. Get a USB switch (~$20)
    4. Plug Each of your computers into the switch's outputs
    5. Plug your keyboard into the switch input
    6. Plug your mouse into your keyboard

    For less that $100 you won't have to by an expensive (up to $500) KVM.

    There are a couple drawbacks:

    1. I don't know of a USB monitor, so you will need a diffe
    • Re:USB (Score:3, Informative)

      by njchick ( 611256 )
      4-port USB+Monitor switch for $78.94 [], thanks to Froogle []
    • The Mitsubishi DiamondPro 900U (diamondfoo, whatever) has a built in usb hub and two usb upstream ports that it switches between when you switch between the BNC & VGA inputs via the simple button on the front.

      only works for a two systems; but if that's all you need this is seriously convenient.

      better hope windows doesn't whine about "you unplugged a device without asking me first" though. don't put anything other than your keyboard/mouse on its hub.

      and kiss some chance of configuring your BIOS goodb
      • Hrmmm, I was just wondering about this. My Diamondtron monitor has a USB hub, and the two-input-button-switchable doohickey, but doesn't appear to have the same functionality.

        I always wondered why two-input monitors didn't also include keyboard and mouse switches. It only seems to make sense, that's all. Why would you want to switch monitors, but not the keyboard? If you had a dual-head *slaps head in frustration at what a Windows user might actually do in order to get multiple desktops*
      • I have a USB KVM setup on my test machines to test our game, and am able to use KB/Mouse as well as multiple game controlers on multiple machines.
    • I use "an expensive KVM" (2x8 matrix, 2 KVM in, 8 computers out) and had horrible luck with wheel mice on the linux boxes (SuSE 8.x) Using USB to go to the linux boxes solved the problem. I am still using PS/2 to go into the Wintendos to free up USB ports. Another issue I had problems with is that some of the wheel mice don't work at all if you use a mouse extension cable (my combination is a 3 year old TrackManMarble+ and a Belkin Matrix2).
    • I use the IOGear MiniView 4-port USB-KVM switch.. Have had it for a couple of years now... I use it with my Mac, Sun Blade, Windows XP laptop, and Linux machine. The Mouse wheel works fine on all of these. It's around $130 at Fry's or online and includes cables (so it's not too expensive)
      Here's a URL on tigerdirect [] for it. Not a recommendation on where to buy, but they seem nice. (and no, I dont' work for them!)


    • expensive?
      I got a cheapo 4 port kvm switch (although it seems to work fine) from It was about $50 and the cables were around $10 each. Each $10 cable has a separate cable for mouse, keyboard and video tied together to keep things a little neater.
      So for around $90 (under $100) you've got the switch and cables for 4 PCs, just supply a mouse, keyboard, monitor and the PCs.
  • What is this? (Score:4, Informative)

    by termos ( 634980 ) on Monday June 23, 2003 @04:44PM (#6277225) Homepage
    Okey, what is this? Isn't this the sort of question you usually ask in a discussion forum or even IRC? I don't see why someone whould make a slashdot article over it. I did a search on google and found many resources for how to fix this, take a look here [], here [] and here []. And if you want to browse the results yourself, here [].
    I've googled and found nothing of real use there.
    I don't have a device like this myself, but from the results I got I'll say it looks quite useful.
    • Re:What is this? (Score:5, Informative)

      by slashkitty ( 21637 ) * on Monday June 23, 2003 @04:57PM (#6277405) Homepage
      None of your posted links have any solutions. I'll save everyone the trouble of reading all those links.

      Link 1: Unfortunately, there does not seem to be a remedy at the moment.

      Link 2: I never found a way to make the wheel work without buying a different switch.

      Link 3: Was about a Different switch

      Next time you post links, don't assume they have meaning full information just because they mention a config file.
      • Mouse reset... (Score:3, Interesting)

        by hughk ( 248126 )
        The main issue that someone else commented on is that wheel-mice have modes.

        Every so often a wheel mouse under Linux seems to hang (i.e., not do anything) under RH 8 and 9. This isn't the system, it is some kind of confusion caused by the mouse. Switching virtual consoles away from X then back again seems to clean things up wonderfully.

        What I would love to know is where is the mouse reset is being generated, i.e. is this X, /dev/mouse or what? Clearly Win either is sending out a periodic mouse reset or

    • Re:What is this? (Score:4, Informative)

      by Jeremy Gray ( 223298 ) on Monday June 23, 2003 @05:11PM (#6277595)

      The point you're missing is that none of the links give an actual solution to the problem. The three best solutions so far (from my research) are:

      • try a different KVM
      • reset the X mouse driver with some script or program that outputs the appropriate reset code to the mouse device
      • reset the X mouse driver by switching to a virtual console and back

      And while the question is phrased as if it should be posted to comp.os.linux.* or somesuch, the underlying issue is valid. The Windows mouse driver is able to compensate for shortcomings in KVMs, while the various open source drivers are not, despite theories that this could be done in the X mouse drivers. There is no solution and no good workaround, so hopefully publicity will inspire someone to find the solution.

  • Hmm (Score:3, Insightful)

    by snubber1 ( 56537 ) on Monday June 23, 2003 @04:44PM (#6277234)
    I have the exact same KVM (only you paid too much for it. is selling it for $20 less).

    I am also running a Debian stable box and an XP box and my mouse wheel works fine on both. However I've had debian boxes that were a nightmare to get the wheel working (running unstable however).

    I suppose my point is that it *can* work given your setup.
  • by XDG ( 39932 ) * on Monday June 23, 2003 @04:44PM (#6277239) Journal
    This may not help your particular situation with your existing hardware, but I switched to a USB KVM switch (with a USB keyboard and USB wheel-mouse) and it works just fine in Windows 2000/XP and Redhat Linux (8.0). There are, of course, other issues with using a USB keyboard if you need boot-time support, but a modern PC motherboard should be able to handle it without much difficulty.

    Best of luck,
  • by ComputerSlicer23 ( 516509 ) on Monday June 23, 2003 @04:50PM (#6277321)
    I've got 3 maybe 5 if you count the ones at work that have exactly the same problem. I've got two of the entry 4 ports, a 2x8 matrix stacked with another 2x8 matrix, and a 4 port pro from belkin. All of them have exactly the problem you describe under Linux (various flavors of RedHat).

    There are two things to check, first turn off gpm. It's never done anything but give me grief in all the time I've ever seen turned on. I know that this will solve problems on several different KVM's I have. I know on one of the KVM's, it fixed all my problems so I could use the IMPS driver without doing the second fix.

    Second, is that something is completely screwed about XFree86 of handling the PS2 mice, you can switch to a serial mouse, but no wheel then. The way to fix the problem, is to get XFree86 to resync/reset with the mouse. After switching from once machine to the next, immediately switch to a virtual console, then back to X, and the PS2 drivers will resync/reset/"do the magic to make it go". I've got no idea what the problem is, or why switching consoles works, but on the various Belkin Switches I've seen that is the fix that works best.


  • Here's my take (Score:5, Informative)

    by MrResistor ( 120588 ) < minus poet> on Monday June 23, 2003 @04:51PM (#6277342) Homepage
    Most modern KVM switches will send a signal that tells the machine that it has a keyboard and mouse plugged in even if you're actually switched to another machine. My guess is that the KMS' pseudo-mouse is just a basic 2-button, so Linux doesn't recognize that it's actually a wheel mouse that's plugged in. Have you tried booting the Linux box completely while switched to it (meaning you don't switch to another box to do something else while it comes up)? That might make a difference.

    Also, check for the ZAxisMapping option in your X11Config (you may have more than one, and the one in /etc might not be the one being used), and/or you might try installing imwheel, which is supposed to fix some mouse wheel in Linux issues. I would probably do both.

    • If this is really the case, a little bit of tweaking (removing something like if(m[0].nAxis == 3)) to either the kernel's PS/2 driver, XFree86, or gpm ought to do the trick.

      Let us know how it goes, because I may be doing a very similar setup in the future! :)
    • Re:Here's my take (Score:3, Interesting)

      by elmegil ( 12001 )
      This is pretty interesting, mostly because I have a related and perhaps backwards question. I have a logitech PS/2 TrackMan Wheel hooked to my Linksys 4-way KVM switch. I have a windows game machine (win98se), a linux router/firewall (mouse irrelevant), a Sun sparcstation (wheel irrelevant), and an occasional Linux machine hooked up.

      The Linux machine has ALWAYS recognized my wheel, regardless--SuSE 7, SuSE 8, RH9, various hardware, and whether the mouse was "active" on the Linux box during boot or not. T

      • Re:Here's my take (Score:3, Interesting)

        by MrResistor ( 120588 )

        All I can say is that with all the KVM (and just KV) switches I deal with at work, everything works best if you boot the machine active. My QNX boxes are especially "sensative", if I don't boot them active I don't even get the extra keys on the keyboard (arrow keys, 10-key pad, etc.).

        I have yet to encounter a KVM switch that truely works as advertised. Then again, my company doesn't buy the good ones.

    • Re:Here's my take (Score:2, Informative)

      by AndyBusch ( 160585 )
      Ack! Imwheel is an ancient crutch. Any reasonably modern software understands the wheel directly. And anyway, if you don't have ZAxisMapping set up to begin with, imwheel won't help.

      Probably, you just got a bad KVM. My IOGear chugs along happily.
    • Just adding additional confirmation to MrResistor's comment. I have experienced the same thing. If you boot the machine while you have it selected with the KVM, the mouse wheel will work fine.
  • I posted something similar about a month ago. In our system room we have an Aten four-port KVM switch wired to a Logitech wheel mouse and a conventional PS2 keyboard. Things only work if the system is setup to use standard PS2 mice.

    The problem is that the KVM electronics attempt to emulate a standard PS2 mouse and when you set your system up and tell it that you have a wheel mouse the KVM sends and receives the wrong codes. So far as I am aware the only solution is to specify that you want your KVM switch
  • linksys tech support (Score:5, Informative)

    by linuxwrangler ( 582055 ) on Monday June 23, 2003 @04:59PM (#6277433)
    I have no problem at all with my Logitech wireless optical wheel mouse running through my Belkin 4-port switch.

    Did you bother with the Linksys support site? Perhaps this [] is the problem you are having.

    The Linksys product description says, "Because they donâ(TM)t use software, the ProConnect Compact KVM Switches are compatible with all major desktop and note-book computers." One might read into that statement that the switch is not altering the electrical signals and that the switch is compatible with all mice. Sadly, that appears not to be the case and although a known limitation they don't mention it in the description. I'd send it back and buy from a company that makes KVM switches that work properly.
    • I am running exactly the same hardware; a Logitech wireless optical mouse, and a Belkin Omni View SE 4-Port switch, and am also having no issues. Attached to this KVM switch is a Windows XP workstation, a Redhat 9 workstation, a Windows 2000 server, and a Redhat 7.3 server. My mouse wheel is working just fine under all of these OSes.
  • Similar issues (Score:4, Informative)

    by nocomment ( 239368 ) on Monday June 23, 2003 @05:03PM (#6277478) Homepage Journal
    I've had similar issues with belkin LVM's working with OpenBSD. Turned out to be a PASSIVE kvm and what I really needed was an ACTIVE kvm. The difference for those that don't know is that the active maintains a signal to the mouse port in effect "tricking" the computer into thinking it was never switched away, whereas passive kvm's will just switch it away and don't really care if the OS notices.
  • I think it's probably just your X setup that's screwed up. I've had similar problems w/X and mice... I have one system @ work that is hooked thru a KVM, and the mouse wheel works fine. Then @ home, I have a system that doesn't have a KVM, and the mouse wheel didn't work. Not sure why X detects it properly sometimes and not other times.

    On my home computer, I had to modify my XF86Config file to make the mouse wheel work right. I changed the line that specified what device was being used for the moose. B
  • The Fix for Me (Score:3, Informative)

    by Jebediah21 ( 145272 ) on Monday June 23, 2003 @06:00PM (#6278182) Homepage Journal
    Mouse wheel support works for me under Linux, but if I switch to another machine with the KVM it will kill the mouse wheel support. It is something about X and the switch (can't remember the details). Try hitting ctrl + alt + f2 or something to goto a new login screen without X before switching to another machine. When you come back to the Linux box do ctrl + alt + f7 to get back to Linux and your mouse wheel should work.
  • by Anonymous Coward
    ...I thought you simply stuck the mouse wheel in the cage and the mouse makes it work on his own...
  • Works fine with Windows ... Doesn't work with Linux? And the problem is ... ?

  • by jonadab ( 583620 ) on Monday June 23, 2003 @07:46PM (#6279079) Homepage Journal
    Section "Pointer"
    Protocol "imps/2"
    Device "/dev/psaux"
    ZAxisMapping 4 5
    • That's nice, but if you run a 3 button mouse on some KVM's you'll loose the mouse for some unknown reason when you switch. Seen it happen. Plus, he knows how to do it (configging a scroll mouse) but is in search of a KVM without this issue.
  • IO Gear (Score:4, Informative)

    by Futurepower(R) ( 558542 ) <> on Monday June 23, 2003 @07:56PM (#6279195) Homepage
    IO Gear KVM's work fine.
  • I have an inexpensive four-port Dakota Scout KVM which uses PS/2 sockets for the mouse and keyboard connections. All the boxes connected to it run SuSE Linux 8.1. I have had no problems at all with switching between console sessions running gpm and X sessions using the imps/2 driver to provide access to the wheel. The only difficult bit was getting X to recognize the correct mouse module (IIRC there was a spelling or capitalization issue with the module name, either in 8.1 or one of the previous versions).
    • Wait a minute I just looked at what you are using now - that thing is selling for less than $50! What a piece of crap! So try a more expensive one instead (Dakota Computer solutions have changed their name to Daxten []. They still sell the model I've got (which has been rock solid), and they now have USB versions as well.

      There is one gotcha with this type of KVM switch - the cables cost extra. The video quality I get is good at 1600x1200, but I did get the special high-definition KVM cables for the connectio

  • by unitron ( 5733 ) on Monday June 23, 2003 @10:24PM (#6280483) Homepage Journal
    Why is it that KVM switches have so few problems with PS2 keyboards and so many with PS2 mice? Why is it that you can hot swap PS2 keyboards but not PS2 mice? Was there anything wrong with serial mice that couldn't have been solved by adding another serial port on IRQ12? If not for PS2 mice many KVM switches could be the much less expensive passive type instead of the more expensive active types.

    Can you tell that I have strong negative feelings about PS2 mice?

    • Why is it that KVM switches have so few problems with PS2 keyboards and so many with PS2 mice?

      The protocols are entirely different, and the PS/2 keyboard protocol is older, simpler, and better understood. It's been a long time since they made any substantial changes to it.

      Nonetheless, few KVMs support the entire PS/2 keyboard protocol. I have tried four different KVMs, all different manufacturers, and not ONE of them can properly support the keyboard of an IBM PS/2 95 running OS/2. You type enter and

  • Fix: (Score:3, Interesting)

    by mikh ( 518181 ) on Monday June 23, 2003 @11:12PM (#6280845)
    Logitech mouse? Most KVM's support only MS Mouse wheel mode, and not Logitech one. You need to switch your mouse it to Microsoft Wheel mode.

    Download imwheel rpm... It includes little utility called setimps2. Put call to setimps2 to your /etc/rc.d/rc.sysinit, at the very top (before it starts gpm)

    In X86Config under mouse put

    Protocol "IMPS/2"
    Device "/dev/mouse"
    ZAxisMapping 4 5

    That fixed it for me, until I switched to Logitech laser mouse, which defaults to MS mouse protocol instead of Logitech one, which works fine without this fix.
  • The kicker is that when the mouse is plugged directly to the machine, the mouse wheel works just fine!

    And that is exactly what I do. I use an old PIII 600E as my home workstation running Red Hat 8.0 and I have my generic CrapUSA USB optical plugged directly into it. In the KVM however, I plugged an old wheeless 3 button ps2 mouse along with the keyboard, so when I switch to the other computer I use the old ps2. It isn't really efficient, but it works.

    When I first set this up, I tried using the USB-PS
    • I tried this on a PC alone, no KVM, and came to the conclusion that MS USB-PS/2 adapters are not the same as the Logitech adapters (I have a logitech usbmouse, sans adapter, and a friend has a MS mouse which comes with an adapter)...

      I can't think why this is, but apparently those tiny things have some builtin assumptions ...

  • Driver issue (Score:3, Interesting)

    by Ben Jackson ( 30284 ) on Tuesday June 24, 2003 @02:45AM (#6281999) Homepage
    I suspect that the KVM initializes the mouse as a generic PS/2 mouse and then pretends to BE a mouse for each computer it is connected to. The KVM is probably ignoring the initialization that it receives (or at least ignoring the extended settings) rather than passing it on to the mouse.
    So it's a driver issue in the sense that the KVM's dumb internal mouse driver is not enabling the mousewheel.
  • I have an Apex Outlook 8-Port KVM Switch (180ES) and it does the same thing: when I switch machines I lose the mouse wheel/buttons, and on the XFree86 machines the mouse wheel produces the same weird behavior that you're seeing (on Windows the wheel does nothing).

    I recently discovered that there's a 'reset' command in the on-screen menu which fixes the problem on the current machine until I switch again. I'm not sure if the problem is between the KVM and the mouse, or between the KVM and the machines, I gu

  • step 1: plug KVM mouse cable into KVM
    step 2: plug KVM mouse cable into computer
    step 3: plug mouse into KVM console mouse port
    step 4: turn on the KVM and the computer

    That is how I got it to work with RedHat Linux 8.0 on one side and Mac OS X 10.2.x on the other side of my KVM
    • Macs don't have PS/2 ports! Yeah well just to make things more complicated I have USB -> PS/2 converter cables too.

      And it still works!
      • The wheel doesn't work with NT in my VMware virtual machine. What? NT doesn't know what a wheelmouse is? Isn't Windows some kind of standard OS with Plug and Play? It works in Mac OS 9!
  • I've been running both with a Belkin OmniCube 4. I have seen that problem in the past, but I've had it working fine for so long that I don't recall what I did to fix it.

    If you're interested in seeing my configs, send me an email.

    I still have a problem with my ThinkPad 390X where it won't recognize the wheel on my mouse (because the BIOS sees the trackpoint that handler doesn't support a wheel.) If anyone has a fix for that, please let me know!

  • I used to have the same problem. I have a cheap KVM switch that does serial mice, but not PS/2. I shared the kbd and monitor between windows and linux, but each machine had a separate mouse. What a pain. But what to do?

    I ended up using VNC between the two, then moved on to running an X server on the windows box and bringing up linux windows there, then finally started using terminal services + rdesktop, and have been hunky-dory ever since. I don't have to use an inferior mouse with the machine I use less (
  • I have a kvm on a few Linux boxes, and when I switch the mouse just quits working totally.
    I have to restart X to get it to see the mouse again.
    A real PITA..
  • Belkin OmniView SE 4-port, Logitech optical mouse. Works with X. Works with Windows 95. Works with Windows 98. Works with Windows 2000.

    Under Windows XP, with the Logitech driver, the wheel works initially. After switching to another system and switching back, the wheel no longer works.

    With the MS driver, the wheel works even after switching but, pressing the wheel down for a third mouse button click isn't supported.

    Sounds like a driver problem. I have just been assuming that it was too unusual a pr
  • Please learn the beauty/efficacy of using a search engine: -8&q=x11+imps%2F2&btnG=Google+Search [] 9.html []

    --- Re: Logitech cordless wheel mouse won't work in Linux
    --- Re: Re: Logitech cordless wheel mouse won't work in Linux -- ben perove Post Reply Top of thread Forum
    --- Posted by: Sivakumar Natarajan ®
    --- Wed, Apr 23, 2003, 07:10:55
    --- Author Profile Edit
  • I've seen this shit before, and (for me) it was a synchronization issue. Basically, mouse movements and clicks are reported as multiple bytes over the ps/2 port. This usually happens when you bump the mouse while switching machines, so half the movement packet goes to one pc, and the other half to the other pc. In X11, I had luck convincing it to re-synchronize by (without moving the mouse AT ALL!) clicking each button in turn once. This usually meant left, right, middle, up, down, though it may be diff
  • My Logitech cordless works just fine through my Belkin Omnicube 4-port KVM to my Linux box, which, like yours, runs Debian testing with a 2.4.20 kernel and KDE 3.1.1a. Scroll wheel functionality is fine. I haven't got the side buttons working, but then I can't think of what I'd use them for.

    I doubt it's the KVM that's causing the problem. It's more likely your X config. However, one hint: when I switch to a windows box and switch back, I have to do [ctrl][alt][f1]-[ctrl][alt][f7] to force X to reinitialis

  • 1) X IS configured correctly. GPM is not running. If I use ps/2 instead of imps/2 in X config file, no wheel but rest of mouse works.

    2) I searched and found 90% of the links posted. The switching VT's works sometimes - but if one os can handle it on the same hardware w/ no special work, it tells it is possible for it to work everywhere, and it's some kind of driver/sync issue. If that makes any sense.

    3) To TheMeld - I'll try the button bit. As I mentioned, VT switching isn't so reliable. :)

    4) Have tried
  • I have a Blkin KVM and my only non server is Linux running X11. The mouse wheel works fine, when I switch the KVM and then come back to my Linux desktop the up scrool stops working while the down scrool works fine. When I restart X11 it all works again. It seems that when I switch on the KVM X11 then starts loosing some of the mouse functionality, but the consoles seem unimpaired.
  • The best KVM experience I got is with a manual USB KVM, [] which connects my G4 and my home-built Athlon box running XP Pro.

    I tried upgrading to a powered USB KVM that had its own GUI, but I ended up returning it. I'm a lefty, and I like to have both mouse buttons set to "click" and pressing the wheel set to "context"-- the KVM intercepted this and refused to let the thing work any other way than left-click/right-context. The mouse would just appear as a generic two-button mouse to my computers.

    Apparently th
  • I've got a Cybex at home and bought a lot of their gear for a previous employer. It worked wonderfully, and the 2 port KVM at home has no problem switching between my main linux system and my occasional-use windows game box, both using the scroll wheel. My only complaint is that I wish it were a 4 port so I could get the firewall and web server on there as well

    At my most recent job, and here where I'm consulting now, they have Belkin KVMs. Crap. I've never had this much trouble ever with a KVM. The mo

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