VAX 11/750 rescued, alas...

J Blaser oldcpu2 at
Fri Oct 5 20:03:42 CDT 2007

The gods smiled upon me, and I was chosen to rescue the DEC VAX 11/750 
that Richard alerted us too about a month ago.  Yesterday I went up to 
collect it.  I think most of us, during a pickup, are mindful of just 
getting the load onboard and away, and it was the same way for me with 
this pickup.  Besides, the unit was literally stuffed so tightly into 
the front corner of their storage that there was no way to examine the 
innards at that location.  A few images can be found at:

Once back on homebase, I finally got a chance to open up the unit.  To 
my horror (it is October, after all), I find just a single board 
installed in the CPU backplane, and one loose q-bus board!  The first is 
a System Industries 9700-6301 with the following significant chips: 
Signetics N8X60N, AMD AM9128 (x2), Motorola MCM93L422PC (x4), TI 
SN74S181N, and about a dozen TI 82S137s with little numbered stickers on 
each.  Otherwise it's loaded with TTL logic chips.  There are no headers 
or other connectors on board, just the backplane fingers.   I have no 
idea what this board is.  I openly admit that I'm a complete {non-uVAX | 
massbus | unibus} novice.  The second board is an MCD MLSI PC-11, which 
I'm guessing may be some kind of dual parallel interface.  I'll have to 
do a little scouting on Bitsavers and Manx to see if I can turn up 
anything useful.

Anyway, sadly, this box is not much more than an empty carcass, without 
any brains.  It clearly was sacrificed to keep other systems alive.  
Still, I would dearly love to populate the backplane(s) and light this 
baby up, but I guessing I'll be hard pressed to find anyone with a whole 
set of spares that I could somehow convince into letting them go.

I don't want to lose an opportunity here, and I'm not saying that I have 
my eye on the local metal recycler just yet, but what am I going to do 
with an empty chassis?!  Now, I should say that the donor was extremely 
nice, and offered to pass along anything related that eventually turns 
up as they dig deeper into their massive pile (12' x 15' x 20', 
literally boxes/cartons/PCs upon boxes/cartons/PCs), but I'm not sure I 
should hope for much.

Am I foolish to ask?  Anyone with a spare set of VAX 11/750 modules?

- Jared

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