An old dream come true: Iris Indigo!

[ajones]

>
> It also uses the same GIO bus as the R3K, different from the Indy's one. 
>   My point is that the CPU is only one part, of several.  To say that 
> makes the R4K Indigo like an Indy is like saying an R5K Indy is like an 
> O2  :-)   It's a question of emphasis, I suppose.
>   

Yes, there's lots more than the CPU.  The Indy and Indigo R4k share a 
lot more than just a CPU.  To build on your example, the Indigo R4k, 
Indy R4k, and Indy R5k all have gio32bis slots.  The Indigo R3k supports 
only gio32.  The O2 supports neither. :)