6 Jun
2005
6 Jun
'05
7:25 p.m.
On 6/6/05, Jerome H. Fine <jhfinexgs2 at compsys.to> wrote:
By the way,
as Antonio states below, this backplane is an 8 * 4
slot from a BA23!!!!!!!! Maybe Ethan's finger slipped
and added an extra "1" after the "BA"?????????????
I can't see that DEC would have converted a BA123,
but I guess that DEC could have done anything at that.
I did not slip - my recollection was that it was not only the BA23
that DEC gummed up... since the BA123 was so expandable (drives _and_
cards) compared to the BA23, that they didn't want someone to buy a
GPX-II for less money than a MicroVAX-II in a BA123, then ignore or
remove the graphics cards and turn the former workstation into a nice
departmental server.
If you were around in those days, you may care to skip the rest of the
message, but if you are wondering what they were thinking, read on...
Back in the day, an unlimited MicroVAX-II in a BA-23 came out at
around $20K (possibly a few $K more), but workstations were well under
$20K. Memory was a big throttle for being able to use the system for
more than a single user (1MB on the CPU board, 2 PMI slots available
in a BA23, with 16MB being max for the KA630) If one could keep the
machine to a max of 9MB, then it effectively limits how many people
can be productive on it. It wasn't until the MicroVAX 2000/VAXstation
2000 that DEC implemented a CPU protection scheme (a jumper on the
motherboard shows up as a detectable variation, so if one is willing
to crack the case - not a problem with something this old - one can
flip-flop a VS2000 to a MV2000 and back). With the KA630 design
(MicroVAX-II), there was no way to enforce a marketing/licensing
scheme except by limiting expansion the hard way.
-ethan