[ale] /proc/interrupts

[hne]

  IRQ 13 was originally designed to "call" the floating point chip, back
when the FPU was seperate from the CPU (the 80286 had the 80287 & the
80386 had the 80387, I don't remember if there was a FPU avail for the
8086).  It uses IRQs just much like any other interrupt drive device
does (com ports, network cards, non-polled printer ports).  Load a
registers, call the IRQ 13, FPU picks up the registers, computes the
numbers, puts the answers back, returns from the interrupt.  

"Dunlap, Randy" wrote:
> 
> I don't think it's an error either.  It's just that IRQ 13
> is associated with floating point exceptions (match coprocessor,
> built-in, or even floating point emulation software).
> 
> ~Randy
> 
> > -----Original Message-----
> > From: Linux Idiot [mailto:esoteric at denali.atlnet.com]
> > Sent: Monday, September 14, 1998 5:52 AM
> > To: Ben Phillips
> > Cc: ale at cc.gatech.edu
> > Subject: Re: [ale] /proc/interrupts
> >
> >
> > Ben Phillips wrote:
> > >
> > > It's not really an error AFAIK, I'm just looking at what I
> > see when I cat
> > > /proc/interrupts.
> > >
> > > On Sun, 13 Sep 1998, Dunlap, Randy wrote:
> > > > Is it for IRQ 13 (hex 0d)?  This is an old AT standard for
> > > > floating point exceptions.  What kind of processor are you using?
> > >
> > > Yes, it is on 13.  It's an old 486SX.  D'you suppose it's
> > there because of
> > > some real error, or because it's an interrupt set up to
> > catch errors if they
> > > happen?
> >
> > Just rebooted my box to win95 and irq 13 is assigned to the math
> > coprocessor... ??
> >
> > >
> > >                       __   _
> > > Ben Phillips         /  '_' )         ,,,    "I wish I
> > could file suits
> > > pynk at cc.gatech.edu   |  | ()|||||||||[:::)   against
> > stupidity. The world
> > >                      \__.-._)         '''    would become a jail."
> > >                                                       --  Cybervox
> >
> > --
> > Until later: Geoffrey         esoteric at denali.atlnet.com
> >
> > You mean you paid MONEY for Service Pack '98????
> >