PDP 11/44 working

From: John Lawson <jpl15_at_panix.com>
Date: Sun Oct 6 21:32:01 2002

  Yesterday (and into the night), I powered up one of the two 11/44
machines rescued from San Diego. Did the usual thing of taking out the
cards, documenting cables, cleaning, dusting, and then turning things up
slow and watching voltages - no worries, the systaem came up and was
subsequently reassembled in it's as-acquired config.

  It boots from two Micropolis 51/4" half-height drives sitting in the
card bay of a card-less 11/23 chassis... which has been re-badged by
Centaur Software. The front panel switches control write-protect, now.
I don't have models right now, since I didn't work on that device yet.
But they connect to a Dilog DU686 controller card - a quad-height card
with one common 34-pin ribbon and individual 20-pin ribbons going to each
(of 2 drives). This is... MFM, no? the original owner called them SCSI
but somehow I think not.... Anybody have Doc on this Dilog card?

  The machine currently runs RSX-11M V4.2 G Build 58, or so it says. File
creations run from 1980 to 1997, when the machine was shut down. The
physical devices are mostly from '79 to '83.

  It has Fortran, Basic, and Oregon Pascal V2 installed.

 There is an RL02 system, working nicely, and couple of multi-line EIA
muxes, one DEC (M7819) DZ11 and a Ditronics 16-line EIA mux.

  There is also a Digital Pathways SLC-1 real-time clock/calendar that
sits in the Console line and responds to certain interrogatories from the
System... fairly funky, IMHO.

  It came with printsets for all major subsystems, and the Blue Wall, and
about 20 RL02 packs, most of which are blank.


  If everything goes as planned, I will bring this machine to VCF5.0 and
let it be Played With.


  And, looking back into the Files, it was Bill Bradford who first brought
this machine to the attention of Chris Kennedy, who referred it to me, and
voila! here it is warming my (pleasantly) chilly garage while we wait to
see if Autumn is going to actually stay for a while. It was pushing 90
here this afternoon... wierd! Should be fixing to snow....


   So - now to wake up the Second System. Since this was a
mission-critical machine, there are actually two complete
identically-configured 11/44a and disk subsystems. The RL02 is shared by
changing cables to the machine in use, and the TTY lines are all hooked up
to a bank of DPDT mini switches (also by Centaurus Software) so that, if
one system crashes, the other can be cut over by changing one connector
and flipping the switches.


  Anyway - not a particularly 'rare' or 'significant' system, but
certainly fun to mess around with. It certainly gets stares from my
nieghbors. One of the local kids looked in while it was running this
evening and asked "what's *that* thing?". I told him it was a computer.

  "No Way!!"


  Cheers

John
Received on Sun Oct 06 2002 - 21:32:01 BST