On 3/10/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
Ethan Dicks wrote:
I think a 11/750 makes a fine single-user VMS
"workstation" ;-)
Never trust a workstation that couldn't roll over you and smash you flat?
I almost had an 11/750 land on me, but I was able to coax it out of
the side door of a Chevy Astro mini-Van (alone) without getting
squished or pinched. That was a fun experience.
I once (with the help of a bunch of other people) was attempting to
unload a DECsystem 5810...
It landed on me as I was kneeling down. I caught it.
I think I've heard people reference this incident on the list. I
didn't know it was quite as spectactular as all of that - sounds like
a combination of luck and quick action on the part of all present.
> Thinking about the whole "11/750
workstation" concept - I wonder if
> one could take a qbus mono framebuffer and hang it off of some flavor
> of Qniverter?
I once asked a question as to whether it would be
possible to build a
VAX 6000-based workstation by hanging a Qbus framebuffer from a Unibux
slot hooked to a VAXBI bridge in a VAXBI slot in a secondary BI cage
hooked to a VAX 6000 through an XMI->VAXBI bridge. The consensus was
that it probably wouldn't work. 8-)
Hmm... I have an 8300 in the basement with a non-working DWBUA (it
used to work, about 13 years ago but that was before the machine got
moved). My recollection of it was that (when it was working), the
DWBUA was ok in a native VAXBI environment like the 82xx/83xx, but
that when you started stacking bus converter on bus converter, it
didn't take much to get things to the point of violating timing
maximums on certain things. We had a problem with a Qbus COMBOARD
being stuck in the same Qbus as a TLZ04 controller on an early model
VAX 4000 since the CPU bus _wasn't_ Qbus, and there were enough subtle
changes that hardware bus timeouts came into play, especially when the
TLZ04 controller "went away" for a bit - I think officially, the
timeouts were too stringent, but had never been a problem up to that
model of VAX.
I have to seriously wonder if you could get traffic from the Qbus,
over the Q/Univerter, over the DWBUA over the XMI-BI bridge (forget
the model #) before something timed out somewhere.
No reason not to attempt it, but if it doesn't work the first time,
the chain might just be too much to handle.
-ethan
P.S. - the problem I'm now having with my DWBUA might be a wonky UET
(Unibus Exerciser/Terminator). The UET has to work perfectly and
respond correctly when the DWBUA talks to it, or the DWBUA fails
self-test. Could be cables, could be bad components, or could just be
the phase of the moon. Either way, I installed a DWBUA correctly
once, and now it appears to have been a fluke. It hasn't worked right
since I moved it. :-( I have the docs, and according to the various
device status registers, it acts like the DWBUA isn't seeing the right
things from the UET. *slaps forehead* I have just the thing to check
it out - a not-yet-assembled bare-board UA-11. I think assembling
that just moved up the priority chain to sometime in the first 1/2 of
this year!