rarest computers

I do not think you understand, perhaps I should clarify. Provenance applies to *individual* artifacts (instances, if you will). It does not apply to kinds of artifacts (classes, to keep the OOP thing going). Nearly all Altair 8800s sat in some geeks' basements, playing tictactoe or some other menial task. Maybe a few did get used for developing some bit of well known software. Likewise, most 5150s were used in the offices of well known (and more now-forgotten) corporations. A few, however, could have been used to write a great American novel or screenplay. Look at your machines as individuals. Where did you get each one? What were they used for? Do you have evidence to back up the claims? You will see that most machines - nearly all - did pretty unimportant jobs in their lifes. I look at mine - one was used for managing parts for GM in Canada. Another did payroll at a steel and bridge company. Another was used in a high school. A few I simply do not know. Anyway, not very exciting. What I am looking for are instances of machines with a exciting history. William Donzelli aw288(a)osfn.org