2015-12-15 3:15 GMT+01:00 william degnan <billdeg...@gmail.com>: > On Mon, Dec 14, 2015 at 1:33 PM, Mattis Lind <mattisl...@gmail.com> wrote: > > > 2015-12-14 17:12 GMT+01:00 william degnan <billdeg...@gmail.com>: > > > > > Just to change the subject.. > > > > > > There were "S" and an "NC" version of 11/05 high profile system. Why? > > > > > > I am curious if any DEC historians here know the reason for two > versions > > of > > > the same DEC PDP 11/05 *high profile* computer (not talking about the > low > > > profile). There are separate manuals for each type. > > > > > > > Age? The NC (and ND if you are in 230VAC area) are in the BA11-D chassis > > which uses the H750 PSU. The same chassis was used by for example 11/35. > > The H750 PSU has partly the same assemblies as the low PDP-11/05 chassis > > and then also a H744. The memory system is somewhat different in that the > > H214 is 8kW and the H217 is 16kW and the former is used in the NC/ND > while > > the S uses the latter. > > > > But of course there can be all sorts of other reasons as well. > > > > /Mattis > > > > > > > > > > Yes I did know that power supplies and RAM are different within the two > versions, being that have both types of 11/05. That's what prompted my > question - *why* did they make these two versions of the high-profile > 11/05? What was one used for vs. the other? *Why did DEC do this*? > > It is simply that as long as the box had the M7260/M7261 CPU cards it was > an "11/05"? (or 11/10) > > Those of you who knew DEC back then may have a perspective I don't on the > subject. Seems to me that they did not care, they just used what they had > available. >
Yes, and my guess that they are of different vintage. The BA11-D is the older box used for the NC and the BA11-K is the more modern box used for the S model. Over the years the memory requirements increased and thus they had to increase the density. I think the NC/ND models are the first 11/05s along with the low cabinet model. The a few years later the S model was added. /Mattis > > -- > Bill >
