simonb> I'm not sure of what a sable is (some internal machine?)

I don't have an answer, but things really got confusing for me when
Digital used the name Sable as the development name for the Alpha
2100.


simonb> I'm pretty sure the 5400 series was the multi-cpu series, not
simonb> the 5800 series.

Sorry, it's the other way around.  The 58x0 was the multi-cpu one.
The 5400 was in a similar case to the 5500, ran at 20/25 MHz (which?)
and I'm pretty sure it didn't have SCSI or Ethernet on the motherboard
(although the definition of which board is the "motherboard" in these
machines can be interesting - bottom line is SCSI and Ethernet were via
Q-bus).
__
David Burren