nice find - now I have a PDP-11/93 question

From: Jerome Fine <jhfine_at_postoffice.idirect.com>
Date: Wed Feb 13 21:58:06 2002

>Gooijen H wrote:

> Many times I read with envy those phantastic finds in the US.
> Now it is my time to get lucky:
> - several 8- and 16-line serial MUXen with distr. panels
> - Q-Bus Centronics printer interface with connector
> - SC-08 Q-Bus (dual) SCSI controller (MSCP/TMSCP compatible)
> with the Emulex doc and the rear connector panel
> - KDJ11-A manual (0.5 inch thick)
> - LA120
> (with flaky electronics and both pin-feeds bands broken)
> - PDP-11/73 with TK50, RD54 (Maxtor) disk and 2 M7551 memory boards
> (but when powered up produced the smell of burning paper ...)
> - PDP-11/93 (M8981-BA) but without documentation.
> AFAIK, the 11/93 was the fastest DIGITAL PDP-11, so I consider this
> a nice addition to my collection. Since the chassis only contained
> in slot 1 A-B: M8981 PDP-11/93
> in slot 2 A-B: M8047 grant continuity
> in slot 3 A-B: M7546 TK50 controller
> and the PSU of course, I moved the TK50 and the RD54 from the 11/73
> into the 11/93 and added in slot 4, position A-B, the RQDX3 (M7555).

Jerome Fine replies:

Yes, you are fortunate. However, such hardware should become available
over time as the PDP-11 is discarded.

I don't believe that you need the M9047 grant continuity card in the second
slot as opposed to placing some other card there. Probably it was easier
for the original upgrade to replace the CPU card with the 11/93, then
remove the memory and substitute the M9047. You could just as easily
remove the M9047 and move all the other cards up one position.

What do the DL interface connections consist of? I have a set from an
11/94 system, but they really don't seem to fit from a hardware point of
view into a Qbus system, in particular, in a BA23 box.

By the way, if you enjoy running the software more than the hardware,
try running under E11 on a Pentium III 800 or similar. I am achieving
10 times the speed of the PDP-11/93. I am in the process of switching
to a "newer" system. This will run W98 (double yeck - but when I run
W2000, the AGP card will not allow 132 character lines - which I value
when I look at a MACRO-11 listing) on a Pentium III 750 with 512
MBytes of memory, more than half of which I will use for a RAM: disk.
Plus I will be using a 40 GByte EIDE drive which can sustain a throughput
of 10 MBytes per second or 600 MBytes per minute. The latter
compares with the ESDI drives on the 11/83 which I have available that
are unable to sustain a throughput of even 1 MByte per second.

I am not knocking 1990 technology however - at the time, a poor 486
was not even close - I am really saying that if 3rd party hardware could
find a market for the PDP-11 to justify an improvement on DEC PDP-11
hardware, was that part of what went wrong with the company that
started it all? As far as I can see, PDP-11 OSs in general and VMS in
particular probably already do (in their particular sphere) what M$ may
be able to do in another 10 years.
Received on Wed Feb 13 2002 - 21:58:06 GMT