Sure there is. "Cool" doesn't
necessarily mean on-topic though. There's
probably lists on the internet somewhere that they can be discussed.
And there are other fora for some machines that _are_ on-topic. I am
quite sure that there are still usenet groups (which are accessible via
the wrb, of course, if you don't have a newsfeed) for some older machines
and OSes.
And there are specific web fora for some machines/classes of machines. To
take a concrete example, the HP9830 is on-topic here (I hope). It's also
on-topic on the forum on the HP calculator mueseum web site.
If you want this list to only be for machines that have nowhere else to
talk about them, I suspect the number of on-topic messages will be
exactly zero.
-tony