Using UX-boards with SBus based machines?

[barmar@Think.COM (Barry Margolin)]

   Date: Mon, 18 Mar 91 17:42+0100
   From: berni@iml.fhg.de (Stefan Bernemann)

   (2) If I try to remember, when Symbolics introduced the Ivory based
   embedded system architecture, they proudly announced their independence
   of a specific bus architecture. 

I don't remember their exact wording, but I interpreted it as independence
from a nonstandard, proprietary bus.

				   There would be "no problem" to adapt the
   Ivory system to a specific "host system bus". Now, when will there be a
   SBus Ivory card? Or am I sitting in a wrong movie - quite happy with my 
   MacIvory and foreseeing a good market for such a UX-baby?

The Sbus is also a nonstandard, proprietary bus.  Symbolics can amortize
the hardware development cost of a VMEbus board over many products: XLn00,
UXn00S, UXn00M (my guess at the name of a co-processor for a MIPS system),
etc.  An Sbus board can only be put in certain Suns.

Yes, the architecture is designed to be bus-independent, but it still takes
work to implement a new board.  Considering how often we tell Symbolics to
stress their *software* expertise over hardware work, and the disappointing
sales of the UX400S line, I could hardly blame them for being conservative
about developing other co-processors.

Also, product cost is a factor.  A UX1200S system costs around $20K.  This
doesn't sound too bad when it's stuck into a $20-40K system, but customers
may be reluctant to buy a $20K co-processor for a $5-10K system (I imagine
many MacIvory customers had to overcome similar feelings).