Personally I work on the basis that 1982 is the cutoff year for
anything interesting Anything newer is only interesting if it isn't
powered by Intel or AMD.
AMD made some very interesting bit-slice chips that I am sure were used
in machines after 1982. Surely those count as 'classics'.
Even if you meant (as I suspect) 80x86 family processors, I would argue
that what I call 'IBM incompatibles' should remain on topic here. Those
are machines with an 80x86 processr running MS-DOS or CP/M 86 but which
are not hardware (and often not BIOS-level) compatible with the IBM 5150.
Things like the HP110, HP150, DEC Rainbow, FTS 88, Sirius (Victo 9000) and
so on.
-tony