UNIBUS RAM with Parity vs. None

[william degnan]

On Oct 10, 2015 12:27 PM, "Eric Smith" <spacewar at gmail.com> wrote:
>
> > Anyone disagree, and if so why did DEC want their 11/05 S to use "D"
model
> > core (D=parity) and not C (C=no parity)?  The PDP 11/40 I have uses C.
>
> The H217D is the no-parity plane, and the H217C has parity.
>
> For the parity to do anything useful, you have to also have an M7259
> module, and IIRC the 11/05 backplane is not wired for it.

Thanks.  I tried an m7259, no dice, but I need to read the manuals
thoroughly as to why and see what changes would be needed.  Bummer because
the 217d almost works