On Oct 18, 12:14, David C. Jenner wrote:
> Subject: Re: Need Info on DEC 11/84 Board, M8190
> CLASSICCMP_at_trailing-edge.com wrote:
> >
>
> > A M8190-AB is a 15 MHz (11/73) CPU with "warm floating point", but
> > *will* accept the FPJ11 as an option.
>
> I have one -AB that has a socket for the FPJ11 and one -AB that doesn't
> have a socket installed. Are these the same board? Is installing a
> socket on the board without one difficult (being it's multilayered)?
Normally I'd say that meant the one without the socket wasn't likely to
work with the FPJ11 even if you fitted it (they omitted the socket for a
reason) but if they have same etch revision, maybe that's not the case.
> I have a couple of 1MB M7458-AH (MSV11-RA) PMI boards. Although the
> Micronotes refer only to MSV11-J boards, I assume that what it has to
> say applies to the MSV11-R also?
Yes, put them above the processor and they use PMI; put them below and they
run as ordinary QBus memory.
> I also have a 4MB non-PMI board. What sort of performance loss do I
> get by using the non-PMI memory? My goal is to run 2.11BSD, so more
> memory may be better than faster memory. (Of course, I can always try
> to find more, faster memory!)
There's quite a difference on memory-intensive tasks -- several tens of %.
But the good news is that 2.11 wil run fine in 2MB. Whether more is
better than faster will depend on how much memory you need, and whether you
often use enough to make it do a lot of swapping to disk.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Received on Sun Oct 18 1998 - 15:40:00 BST