RK611 schematics

[Tony Duell]

> There is also a "BA11 expansion box sided" box from Plessey, but
> I have not yet looked at the details of the machine, so that
> Plessey box is a black box to me at this point.

Plessey made various Unibus (and Qbus?) devices that were more-or-less 
DEC compaatible. At least one of the RAM boards in my 11/45 is a Plessey.

I also have a PLessey 10.5" high expeansio box on that machine. It's 
nicer than the DEC one in that you can fit 3 9 slot backplanes across it 
(or 6 4 slot). The power distribution is non-standard (9 pin mate-n-locks 
for each backplane) but that's easy to sort out.

-tony