[rescue] upgrading VAXstation memory

Jonathan Patschke jp at celestrion.net
Tue Apr 20 22:46:48 CDT 2010

On Tue, 20 Apr 2010, Patrick Giagnocavo wrote:

> I have a 4Mbyte VAXBI board numbered T1019, but I think that must be for
> earlier VAXen.

Not just earlier, but VAXBI is an actual VAX system/peripheral bus,
whereas the RAM slots in a VAXstation 4000 are on a special-purpose
processor-to-memory bus like you'd see in a typical workstation or PC.

VAXBI is a neat bus.  Beyond being self-configuring (ie: plug-and-play)
and possibly being a peer with the CPUs, the ZIF connector (what a neat
idea!) carried both the connections to the rest of the bus and connections
to the I/O bulkhead.  While this gave the card itself a very clean layout,
also also meant you had bulkhead kits to keep track of along with your I/O
cards: one without the other was useless.

XMI did the same thing, only faster.  It's a shame that installing cards
in PCs and Macs still involve screws and dangling cables and lots of other

Jonathan Patschke  ) "Oh, judge, your damn laws: the good people don't
Elgin, TX         (   need them, and the bad people don't follow them,
USA                )  so what good are they?"          --Ammon Hennacy

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