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SubjectRe: Should I use Linux to develop driver for specialized ISA card?
Fred, I'd check out the faq on rtlinux...

"Worst-case times are
about 15microseconds between the assertion of an interrupt
and the starting of the realtime handler on a generic x86
PC"

there where patches in the 2.2 era (some kind of midi related flamefest
occured at that time) that would take the average in a 2.2 kenel down to
25Us but the worst case was still fairly large...

what a rtos buys is not generally performance but a much higher
level determinism than what we can arrive at.

joelja

On Tue, 4 Sep 2001, Fred wrote:

> I'm curious, Alan, Why? I'm a hardware developer, and I would have assumed
> that linux would have been ideal for real time / embedded projects? (routers
> / controllers / etc.) Is there, for instance, a reason to suspect that linux
> would not be able to respond to interrupts at say 8Khz?
> of course I know nothing of rtlinux so I'll read.
>
> TIA
> Fred
>
>
> _________________________________________________
> On Tuesday 04 September 2001 10:15 am, Alan Cox wrote:
> > > The moving parts of the plotter are controlled by ISA card that generates
> > > (and responds to) interrupts on each movement or printing event.
> > > The interrupts can be generated quite fast; up to frequency of 4kHz.
> >
> > Thats fine. The issue you might need to consider is how long you can wait
> > between an irq and actually excuting the handler. If that is very tight
> > then you may want Victor Yodaiken's rtlinux
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