Re: mouse-pointer acting weird
Probably your computer's board has no integrated COM port, so you are
using an additional multi-io card. Aren't you? Probably this card uses
an old UART 16450. Isn't it? You can test it, by typing "dmesg | less".
You should see something like this (this is displayed by my machine, as
you can see I have two integrated 16550A ports and two 16450 ports on
multi-io):
Serial driver version 4.13 with no serial options enabled
tty00 at 0x03f8 (irq = 4) is a 16550A
tty01 at 0x02f8 (irq = 3) is a 16550A
tty02 at 0x03e8 (irq = 4) is a 16450
tty03 at 0x02e8 (irq = 3) is a 16450
The problems you experience are probably caused by fact, that the old
16450 UART has no FIFO input buffer. If your machine is heavily loaded,
some bytes sent by the mouse are not received quickly enough and are
overwritten by the next ones. I can see two solutions:
1) Upgrade your COM ports to 16550A (change the motherboard or buy an
additional COM or multi-io card). This is an expensive but total
solution.
2) Give the highest priority to COM interrupts. You can do it with
irqtune, which is the part of hwtools package.
In the typical case just add the "/usr/lib/hwtools/irqtune" line to one
of your startup scripts in /etc/init.d.
Read the /usr/doc/hwtools/irqtune.html after the installation of
hwtools.
I hope it will help
Wojtek Zabolotny
wzab@ise.pw.edu.pl
On Sat, 27 Feb 1999, Roy-Anders Larsen wrote:
> I am running Debian 2.0 (slink) on a 486DX33 with only 10MB RAM and my
> computer is often working hard (having to make use of a lot of virtual
> memory). I am using a three-button mouse running the MouseSystems
> protocol in Xwindows and I am running gpm with -t msc.
> As long as there is not a heavy load on the computer, the mouse works
> fine. Also in windows3.11 on my DOS partition, the mouse never acts up.
> However, when the load gets large on the computer, the mouse starts
> 'jumping' a few inches left at a time. Occasionally it will jump a few
> inches down also. This only happens if I try moving the mouse.
> It happens both with gpm on a virtual console and in X.
> Have anyone experienced the same thing or have any clues about why this is
> happening ? Anything I can do to help it (software-wise) ?
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