I doubted their existence because i could never find reference to this
mythical beast anywhere, but they are mentioned in the Ultrix source. 
Since then, i do have confirmation of the existence of at least one! Its
model name is PMAC-AA. The owner is not sure if it was only used
internally at DEC or not. 

happy hacking,
isildur


On Wed, 24 Nov 1999, Simon Burge wrote:

> Jason Thorpe wrote:
> > Comments I've seen elsewhere indicate that there are some ibus models
> > which have multiple dc chips in them.
> 
> I believe you can get a expansion serial board for the 5100, but I've
> never seem one...