> > I seem to remember a discussion somewhere (maybe on the Microchip
> > forum) about whether any of the PICs had an atomic test and set
> > capability.  The consensus seemed to be that this was not possible.
> 
> Why is it not possible at the very least by temporarily disabling
> interrupts?  Also the 30F do have a bit test and set instruction.

It is *possible* to do preemptive multitasking. I just can't see
any reason to actually use it.

When I use a PIC, I want real-time performance. So I use interrupts
for anything external and a loop in the main program that checks to
see if any of my interrupt routines need more processing. I only
use that if my interrupt routine is going to take too long and then
it just does the minimal amount of processing necessary and sets
a flag for the main loop.
-- 
D. Jay Newman           ! Author of:
jay@sprucegrove.com     ! _Linux Robotics: Building Smarter Robots_
http://enerd.ws/robots/ ! (Now I can get back to building robots.)
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