Most likely they are going into existing products that were designed a
    couple of years ago and are currently in volume production.

Hmm.  That's an interesting question in general...

Is there a nice table somewhere that describes which of the newer PICs are
direct or near-direct replacements for older chips, along with suggestions
for retaining compatibility or "porting" (in either direction)?

I mean, suppose I decide to build a project described in an old magazine or
web page or PICLIST email message that uses one of these largely-superceded
parts (16C84, 16C71, etc) I certainly would prefer not to have to hunt up a
supplier for an uncommon and unattractively priced PIC variation if I can
just drop in something more modern.  Likewise, suppose I find a good deal on
some obsolete part (the 16C71 being a particularly good example, since I
purchased a small stock of them from another piclist member for <$2 each
some time ago :-), but want to allow using a newer (cheaper MSRP) part if
and when your stock runs out.  (People keep asking about the cheapest PIC.
The cheapest PIC is the one you can find a deal on on the "surplus" (loosely
defined) market; but that's no way to price or budget a production
design...)

Finally, there's the case of wanting to do design with a flash part, with
the option of putting in a cheaper (more secure?) OTP part for production.
(I guess all the flash parts have 14 bit cores?  That makes it a bit tougher
to aim the production at 12bit core parts...)

BillW

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