diminish their importance.  Each of us KNOWS what the
most important and
 significant machine was. 
 So I? I am not sure I do.... 
 
 Although you did just make a reasonably good case for the HP9830   :-) 
 
I consider the HP9830 to be _a_ significant machine, but by no means the
only one.
And FWIW, I consider many machines that I positively dislike the design
and/or construction of to be historically important.
-tony