Matt Kansas "kangas@anise.ee.cornell.edu" wrote:

>Perhaps in later models, but I've cracked one of these open... and the
>scsi board (w. dual ncr5380s) is a *seperate* board, connected to the
>motherboard via a ribbon cable that looks suspiciously like the ribbon
>cables going board-to-board in the 3200 (which I've also had open).
>This scsi board is bolted on top of the aluminum pan which sits over the
>motherboard (on the 3100).

The MicroVAX 3100 (and VAXstation 3100) systems do not have a Q-bus. They do
have one or two SCSI busses (depending on the exact model). Where the SCSI
interface is supplied via an add-on board (e.g. uVAX 3100-10/20, VAXstation
3100-30/38 but *not* VAXstation 3100-76) the add-on board is not usable in any
Q-bus MicroVAX or VAXstation (3200/3300/3400/3500/3600/3800/3900).

>Which is what is commonly called "Q-bus"? (in the 3200)
>	- the ribbon cables connecting cards (aside from a seperate
>	similar-looking cable for the memory boards)

Apart from the CPU-to-memory over-the-top connector ribbon, other options use
similar ribbons where the option is spread over multiple boards: the VCB02
(QDSS) graphics interface (M7169 and one or two M7168 boards) and the KDA50
(M7164 and M7165 IIRC) are two that spring to mind.

>	- the slotted backplane

Part of the slotted backplane is the Q-bus, exactly which slots are Q/Q and
which are Q/CD depends on the enclosure you have.

There is no Q-bus option which is of any use in a MicroVAX or VAXstation 3100.

Antonio Carlini                            Mail: carlini@marvin.enet.dec.com
DECnet-Plus for OpenVMS Engineering
Digital Equipment Corporation              Worton Grange, Reading, England