M8650 async board problem

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Sun Dec 23 04:53:22 2001

On Dec 23, 1:22, Pete Turnbull wrote:
> On Dec 22, 23:15, Tony Duell wrote:
> > As the fault wasn't on the M8650, why did they cut that track? Did they
> > just never want interrupts?
> I've no idea. It wasn't cut by the previous owner; he doesn't know why
> either.

I've just realised something. The machine was used in a real-time process
control system in the pharmaceutical industry. If that system was designed
as a "hard" real-time system, then interrupts would be verboten, as then it
would be impossible to calculate the worst-case execution times for
scheduling routines. I guess this was built not very long after the
Flixborough disaster in 1974 -- an event still used as an example in
safety-critical systems design courses. My guess is the designers just
eliminated all the unlikely problems they could, as well as the likely

Pete						Peter Turnbull
						Network Manager
						University of York
Received on Sun Dec 23 2001 - 04:53:22 GMT

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