help with PDP 11-34

[Glenn Adams]

In article <125 at noscvax.UUCP>, mason at noscvax.UUCP (Nicholas B. Mason) writes:

> 
> Hi.  I need some help.  We have a PDP 11-34 system
> and need to find someone who has used the enable on the
> memory management expansion card to expand the system
> memory to 1 MB so we can run 2.9 BSD.

First of all, you don't need 1Mb of memory to run 2.9BSD on an 11/34.
You can run an overlaid kernel (8 overlays) with 124Kw of standard memory.

However, I would recommend that you buy a Nishho N1100 CPU board to replace
your 11/34 CPU.  It uses the J11 Chip set and runs with 2Mb of memory.  It
also contains 2 serial line units and the line frequency clock.  All of this
is located on a single hex module.  Its cost is $8500.00 for the 2Mb version
and $8000.00 for a 1Mb version (you can plug in your own chips to upgrade
to 2Mb).  I have been using one with 2.9BSD for about 3 months and like it
quite a bit.  Since the J11 uses a split I/D address space, it solves a lot
of problems with the 11/34.  In my system, it replaced 8 cards:  Datapath,
Control, FP11A, 124Kw MS11, Bootstrap/Terminator, Front Panel Interface (KY11B),
and two DL11Ws.  Besides opening up previously used backplane slots, it also
uses 8.0 Amps at +5V whereas the DEC hardware used 28.2 Amps.

In terms of performance improvements, I've benchmarked it with the Dhrystone
test as follows:


   SYSTEM      CPU		   O/S          Compiler	WO/REG  W/REG

 PDP 11/34A	-		UNIX/2.9BSD	cc		 446	 500
 NISHO N1100  DEC-J11		UNIX/2.9BSD	cc		 537	 617

The kernel in the above tests was configured identically as an overlaid kernel
and did not take advantage of the extra memory of the Nishho.  Therefore,
this data reflects a speedup stricly from the CPU.  Overall system performance
will be greatly improved by using a non-overlaid kernel and the full 2Mb of
memory.

The board plugs into your standard DEC backplane with very minimal backplane
rewiring.  (At minimum, you must remove one wire on the backplane; at most,
four wires must be removed and 12 wires added).  In fact, you don't even
need a CPU backplane, it will plug into a standard UNIBUS backplane!

For more information, see "Late-Life Kicker" by Geoffrey L. Cohler,
Digital Review, September 1985, pp. 71-74.  The following are addresses
for the manufacturer and distributors:

	West Coast:	Nissho Iwai American Corp.
			700 S. Flower St.
			Los Angeles, CA  90017

			(213) 688-0600

	East Coast:	MCS Computer Products
			P.O. Box 635
			Shelburne, VT  05482-0635

			(802) 985-2911
-- 

Glenn Adams
MIT Lincoln Laboratory

ARPA: 	glenn at LL-XN.ARPA
CSNET:	glenn%ll-xn.arpa at csnet-relay
UUCP:	...!seismo!ll-xn!glenn
	...!ihnp4!houem!ll-xn!glenn