>
> Byron A Jeff wrote:
>
> > All the other PICs are EPROM based with an algorithm that requires 100
> > microsecond (uS) programming pulses.  The problem is that most PCs
> > can't easily be pinned down to delays that short.
>
>   Just a little nit-pick, sorry!  The PC is *eminently* capable of doing
> this.  A certain variety (not the same as "most") *popular PC operating
> system* cannot be pinned down to delays that short with better than 98%
> reliability.

Sorry Paul, you're correct. It's just that the two can be seen as a unit
from the applications standpoint. It doesn't matter which part of the system
causes the problem, just the fact that the problem is caused.

>
>   I don't know if I ever posted this as a result of my tests.  I *can*
> get this level of reliability on a machine running W95, and with about
> 4us jitter (i.e., about 99% of pulses are within 4us, but the occasio=
> nal
> one is stretched as much as a whole clock tick).  A crude retriggerable
> 4us monostable (charge pump) could however be used to overcome this.

I guess I'm arguing that instead of fighting the PC/OS combo that it's easier
to program a 16F84 which can easily handle the timing requirements.

BAJ