If it looks like a PC-clone (vertical metal strips for
the expansion
slots at the back), then it's either a boring PC-clone or one of the
_very_ interesting Whitechapel machines :-)...
Seriously, PC-clones shouldn't be too hard to recogise, particularly if
you can look inside the case.
PC clones I can avoid without regret, its the S100 chassis that litter some
swapmeets I wonder about. Or for example one of my friends recently
scrapped for gold a bunch of older Sun spares (out of the sealed static
bags and padded boxes, and into the scrap bins). Lots of those 2900 series
chips in that batch.