On 28 Aug 95 at 21:25, Norman Fick wrote:

> I need to do a SIN and COS function on the 16C74. Does anyone know
> about a routine out there (I don't feel up to re-inventing the
> wheel!!).

Norman:

Easiest way is with a lookup-table.  To save space, you can store
just one-eighth (or one-quarter -- it's easier) of a full sine wave,
then read it backward and/or flip the sign, to get the full period.

You may also want to look at different algorithms for whatever you're
doing... If you were drawing circles, for instance, most people would
assume that sines and cosines were necessary, but the Bresenham
algorithm doesn't even require division, let alone any trig
functions.

> A question for you guys who know-it-all. What are the
> dissadvantages/advantages of using a PIC (in general) as opposed to
> using the Motorola HC11 mcu. I am quite familiar with the PIC's, but
> have heard many good reports about the HC11's. (Please try to be
> unbiased in your answer :-) )


Depends on what you're doing, and on which PIC (and which HC11)
you're comparing.

The only PIC comparable to any HC11 is the 17C4x; the other PICs are
much less capable.  Even the 17C4x is no match for the high-end
HC11s.

In general, PICs are faster, lower-power, cheaper in OTP versions,
and more readily-available than comparable Motorola and Intel MPUs.
They run at lower voltages and generate less RF noise, too.

On the other hand, there's much more documentation (from the
factories and from third parties) available for the other chips,
their development tools are more numerous and more mature, and
they're second-sourced.

There are many more people who use Mot/Intel parts, so if you go
looking for a job, Moy/Intel experience will probably be more relevant.
On the other hand, engineers with PIC experience are still rare
enough that if you do find a job where PIC experience is necessary,
you'll likely command a premium.

-Andy