Hi Gunther,

I know I have said this before, but I have and will scan in the 11/785
Installation manual that covers the CPU upgrade. I will try to do 
some tonight.

According to the upgrade manual:
    Upgrading the KA780 to a KA785 consists of replacing the CPU 
    cardcage and backplane assembly, inserting new CPU modules, 
    replacing the memory board in the LSI-11, and attaching a new 
    logo to the CPU cabinet.

So you need the 11/785 card cage/backplane and a new memory
board for the console computer. No changes to power supplies.

I would think that it would be hard to source the new card cage/
backplane and LSI-11 memory board, but if you can get your hands
on a working 11/780 take it! They are really nice old hardware, its 
only 0.5 of a VUP (although when you compare 1VUP to 1.5VUPs 
its 33% increase).

Regards,
Tim.

> Hello,
> 
> I know some of you are former VAX field service technicians or
> have other deep working knowledge of this: what exactly (!)
> does it take to upgrade a VAX 11/780 to a VAX 11/785 (or
> 11/780-5 as it was called.) I believe this includes changing
> the SBI backplane. But what else does it include? Is the
> console computer any different? Power supply?
> 
> As you probably all know, I have the 11/785 board set on
> hand but no cabinet. Now I have the chance of transporting
> one or two 11/780 accross the country. Those are in real
> good shape as I gather (were stored inside!) So I figure I
> rather have a nice 11/780 than a rusty incomplete 11/785
> that lacks a console computer. And with some chance I can
> upgrade one to an 11/780-5. So, what does it take?
> 
> thanks for your advice,
> -Gunther
> 
> -- 
> Gunther Schadow, M.D., Ph.D.                    gschadow@regenstrief.org
> Medical Information Scientist      Regenstrief Institute for Health Care
> Adjunct Assistant Professor        Indiana University School of Medicine
> tel:1(317)630-7960                         http://aurora.regenstrief.org
> 
>