"Peter L. Peres" writes:
>16C54,57 and 12C508,509 have the same 12 bit core.

        I was once told several years ago when I didn't have an
emulator for a 12C509, that I could write the code as if it was for a
16C54 being sure not to use anything that wasn't common to both PIC's.

        The situation is kind of like what those of us who used to
play around with the Apple II in the late seventies dealt with.  You
could write all kinds of assembly-language programming for the 6502 to
decode serial ASCII, play music, you name it.  The routines
could be made to work but any changes to the code had to be
accompanied by lots of tweaking of the delay counters and making sure
that branches were balanced with the right number of no-ops so your
loop wouldn't run at different speeds depending upon transient
conditions.

        I remember designing projects with the NE555 timer chips and
being frustrated that one could almost do this or that function with
just the NE555, but the trigger or the output was the wrong polarity
or maybe you needed it to hang for the time the trigger was held in
one state and then give the one-shot effect for X amount of time after
the trigger was released.  One can certainly write applications for
the 12C509's and 16C54's that do those things and a lot more and all
the IO polarity is whatever you need it to be.  That's pretty cool
even if it is several years old.

Martin McCormick WB5AGZ  Stillwater, OK
OSU Information Technology Division Network Operations Group

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