The term "classic" has been bantered around quite a bit here. I
would presume the term to mean computers that have special merit and have
stood the test of time. I would preclude ANY IBM fully compatible computer
as so many exist in all forms. 
What would I consider as being a "classic"? Obviously, the very
first kit systems such as the IMSAI are classics and, in fact, are still
being manufactured! The original TRS-80 computer has to be a classic as is
the Apple ][. The original Atari 400/800 systems are classics. The
Commodore 64 is definitely a classic with near-cult status. The Amiga A1000
is a classic but the A500 or later shouldn't be considered as such. The
same goes for the original Mac or Lisa computers. Don't forget the mention
of famous minicomputers such as the PDP series or VAX! This is only a
partial listing with many more machines worth mentioning. Obviouly, beauty
is in the eye of the beholder. RLE 

--- Maximus/2 3.01