[ltp] CMOS Battery and Dodgy Mouse?

[Tod Harter]

It is certainly not unheard of for this sort of thing to happen. These 
batteries going down can have all sorts of odd effects. I remember that Amiga 
2000's would become completely wonky when the CMOS battery went dead. I 
forget the exact behaviour or the entire explanation of why it was, but there 
was some chip which would not properly time some output when the voltage on 
that line was low because some engineer just happened to need a +5v and that 
was the handy available source of power!

PC motherboards of various ilks have somewhat similar quirks. 

On Sunday 20 July 2003 11:42 am, Rob Smith wrote:
> ----- Original Message -----
> From: "Huntress Gary B NPRI" <HuntressGB@Npt.NUWC.Navy.Mil>
> To: <linux-thinkpad@linux-thinkpad.org>
> Sent: Sunday, July 20, 2003 9:56 AM
> Subject: [ltp] CMOS Battery and Dodgy Mouse?
>
> > My daughter was using my 600e today and found that the pointer was jumpy
>
> and erratic.  I ended up having to ctrl-alt-backspace to terminate X and
> then I began to investigate.
>
> > The problem with the mouse persisted in bash, so I restarted gpm with the
>
> same result.
>
> > I rebooted and went into seutp, ran the system test and received the
> > error
>
> regarding "low backup battery" and now I have a new battery on order.
>
> > Now the interesting thing is, I removed the backup battery and rebooted.
>
> Of course I got an error and was kicked into the bios setup....but here is
> the odd thing (to me):   The mouse is *still* jumpy and erratic in the BIOS
> setup with no (apparently bad) battery.
>
> > Am I chasing two problems?  And if so, what else might cause a jumpy
> > mouse
>
> in BIOS?
>
> > Regards,
> >
> > Gary H.
> > --
>
> Remember that you are receiving the warning because the system sensed a low
> voltage condition from the "backup battery" or more commonly referred to as
> the "CMOS battery". By disconnecting it, you just dropped the voltage
> signal down to 0.0 volts. Of course, seeing that this is more of the same
> thing to the machine's electronic circuitry, you are going to get more of
> the same result. I hope that this makes sense to you.
>
> Rob Smith

-- 
Tod Harter
Giant Electronic Brain
http://www.giantelectronicbrain.com