On Dec 14, 21:35, Jerome H. Fine wrote:
> > Of course. The dialogue is in the ROMs, after all, and people did
> > upgrade them (to get the ability to boot newer devices, for
example).
>
> And DEC did as well, as far as I know since the upgrade
> looks like an official DEC job.
Very possibly, though it's often impossible to tell who actually fitted
the replacement EPROMs -- DEC sold them to people on self-maintenance
and to third-party maintenance companies like the one I worked for.
> I failed to make my point so that it could be understood.
>
> I was trying to say that within each board specification
> (i.e. all PDP-11/73 quad boards as one of the 3 groups),
> there were still variations. There were probably many
> variations for the PDP-11/73 or the M8190-AB board
> over the years while the boards in the PDP-11/93 group
> might have had just a few. But, just saying an M8190-AB
> is not sufficient to be able to determine exactly what was
> present.
Ah yes, I see what you mean.
> And that is quite a separate issue from whether or not
> PMI memory was or was not used with the M8190-AB
> or the M8190-AE boards. RT-11 would report both
> of these boards as a PDP-11/73B Processor when the PMI
> memory (or regular memory) was installed below the CPU.
> If the PMI memory was installed above the CPU, RT-11
> reported both boards as a PDP-11/83 Processor.
Yes, because that's about the only useful distinction -- the speed
increase brought by PMI memory is more than the clock difference
between 15MHz and 18MHz -- and of course if placed after the CPU, even
a PMI-capable memory board operates as normal Q-Bus memory.
> However, perhaps there is one area where we each
> tend to have our preference. Since I am an RT-11
> software addict, I don't really care what hardware
> is being used. In fact, the faster the better in most cases.
>
> Some people like to hear the original fans turning and
> are not comfortable with a system that runs 100 times
> as fast as the original hardware.
Ah, I like to poke the switches, see the lights and hear the fans :-)
--
Pete Peter Turnbull
Network Manager
University of York
Received on Mon Dec 15 2003 - 15:52:16 GMT