Hi Reg and others,
Although it is true that Macs are "personal computers", the terms "PC"
and "IBM compatible" are generally used to refer to IBM's trademark:
the "IBM PC(tm)", circa 1890's...or more like the 1980's. This is the
platform on which all the "PC clones" (a.k.a. "IBM-compatibles") are
modelled. So, "Wintel" machines are still called "IBM-compatible PCs"
(or "IBM PC-compatibles"). My understanding is that the chips inside
IBM's PCs(tm) have *never* been made by IBM (i.e. IBM used Intel's
chips for their PC, and all IBM-compatible clones would therefore
have had to do the same). (I'm ignoring AMD for the purposes of
this explanation.)