I have been able to bring up the DECnet-RT images, that Jay posted a few weeks ago, on OpenSIMH. Below are my notes on how to get it running.
John.
Notes for getting DECnet-RT V2.1 running on OpenSIMH
NOTE: DECnet-RT is a phase III system so it does not understand Phase IV areas
and can only address nodes in the range 1 - 255. If you attach it so a
Phase IV router (e.g. PyDECnet) it can be accessed as node nnn in the
area that the router is in. If you are bringing it up as part of a
larger network (e.g. HECnet) make sure you "own" it's address otherwise
you may cause routing problems.
I have tried running DECnet on most versions of RT-11 from 5.0 to 5.7. Any
version after 5.4D has various problems with file/terminal I/O.
The available images will only run on an unmapped system with
background/foreground support. This means that everything; monitor, disk
driver, DECnet and application must fit in 28KW. Later versions of RT-11
slighly increased the size of the monitor and/or disk drtiver so that NFT and
FAL will not fit in memory. DECnet-RT requires features that are not provided
in the distributed monitors so you will have to generate a new monitor (See
RT-11 System Generation Guide). You can take all of the default answers except:
"Do you want the single job monitor?" Answer N
"Do you want device time-out support?" Answer Y
"How many extra device slots do you want?" Answer 4
Once you are running the new monitor, copy all the files from the 3 RX50
floppy images (RX0808.IMG, RX0809.IMG and RX0810.IMG) to your system device:
COPY/SYS DUx:*.* SY:
The system is configured to use a DLV-11 (CSR 176500, vector 300, priority 5)
for network access. Add the following lines to your OpenSIMH .ini file:
SET CPU 11/23
SET DLI ENA LINES=1
SET DLO0 DATASET 8B
ATTACH DLI LINE=0,SPEED=115200,CONNECT=<IP ADDR>:<PORT>;NOTELNET
If you are attaching to PyDECDnet, the associated configuration line would be:
circuit dl-0 DDCMP --mode tcp --local-port <PORT>
where <IP ADDR> and <PORT> need to be set according to your network.
The network configuration is in a file called "CETAB.MAC". We can use CFE
(Configuration File Editor) to change the node name and address (in this case
to node name RT11 at address 111):
.R CFE
File name <SY:CETAB.MAC>:
CFE>LIST EXEC
Executor permanent characteristics as of 00:00
Identification = ERC PDP-11/23
Name = ERC23, Address = 124
Host = 124, Maximum links = 4
CFE>DEFINE EXECUTOR NAME RT11 ADDRESS 111 HOST 111 IDENT "RT11 11/23"
CFE>LIST EXEC
Executor permanent characteristics as of 00:01
Identification = RT11 11/23
Name = RT11, Address = 111
Host = 111, Maximum links = 4
CFE>DEFINE NODE 112 NAME REMOTE
CFE>EXIT
The last DEFINE command defines nodes in your DECnet network so you can connect
to them.
To load DECnet:
.ASSIGN SY NT
.R NCP
NCP>SET SYSTEM
NCP>SET EXECUTOR STATE ON
NCP>SHO EXEC
Node volatile summary as of 00:00
Executor node = 111 (RT11)
State = On, Identification = RT11 11/23
NCP>EXIT
If you want to allow incoming connections run NJS (Network Job Spawner):
.R NJS
?NJS-I-Network Job Spawner Active
and then it will report each program activation.
The following programs are available:
NCP - Network Control Program
NFT - Network File Transfer
TLK - Interactive talk with another (remote) terminal
RMT - Remote terminal (RSX)
RVT - Remote terminal (VMS)
CED - Dumps internal DECnet data structures (/AL dumps everything)
The following servers are available:
NML - Network Management Listener (use with NCP)
FAL - File Access Listener (use with NFT)
LOOPER - Loop testing (use with NCP LOOP NODE name)
Hi guys,
Since Friedhelm build his Nixie clock with tube electronics in 2005:
https://www.jogis-roehrenbude.de/Leserbriefe/Bruegmann-Digital-Roehren-Cloc…
I'm more or less trying to build a "tube" Nixie clock with neon lamps
and/or trigger tubes/thyratrons instead of vacuum triodes.
In 2005 I told Friedhelm that this is a nice clock..but build the wrong
way. To tube times one build dividers using monoflops and ring counters
with decatrons and so on..not with vacuum tube Flipflops.
We've calculated the energy costs for this tube clock of approx. 400
Deutschmarks in 2005, don't really want todo this today..especially for
the country with the dumbest and worst energy politics world wide..
green ideology politicans here has blown up the worlds best and safest
nuclear power plants to dust...
...
Since I've got approx 1000 of small chinese neon bulbs in the meantime,
I've tried to build Ring counters out of the neon lamps..it works, but
not that good, since the differnece between the Ignition voltage and the
Extinguishing voltage is to small on this tubes, the counters are
unreliable.
A few years ago some russian trigger tubes TX4b got available, that are
small pencil tubes with only 3,5mA Ia max. Those tubes have a bad
reputation in rossia because they where put in to the vertical
deflection circuit of some soviet made black and white TV sets and it
was a bad design, the tubes where overloaded and don't lasted for very
long. Another type, the MTX-90 was more often suggested and used.
After some years the box with the TX4b fell into my hands and I'm
searches again in the russian Internet for possible uses of the TX4b in
Ring counters..the circuit design depends on the parameters of the tubes
and isn't really that simple. I've searched for examples and finally
found some morse transmitter device with "digital electronics" build out
of the TX4b tubes.. russians wrote that this thing was unreliable :-)
Nevertheless I found what I'm searching for, an schematic and a
description in russian, english and french.
..so I have an working ring counter here next to me on a breadboard. :-)
There is still an MPSA42 used as an pulse former in the clock circuit
that I want to change agains a trigger tube. I need an Ide of an circuit
that gets triggered on approx. 30-40V and outputs an rectangle pulse of
lets say 60V and 10-30µs duration to properly trigger the ring counter,
using possibly only one trigger tube.
I think no one knows that for now..but I'm very grateful for links
to older literature on this topic.
approximately in 2000 I'm parted out old hp tube counters, the displays
where "thermometer Displays using 10 pcs. of neon lamps, one for each
number. The counters used 4 12at7 type "digital" tubes (don't remember
the exact type for now) with biquinary output to the neon lamps.
Later hp counter modules used the very same schematics and the neons and
one hybrid photoresistor module in front of the neons as decoder to
drive nixie tubes. I've tried it already in the past with the neon bulb
ring counters.. a cheap photoresistor in a balc schrink tube that was
put onto the neon lamp can switch a nixie..it works flawlessly.
Tried this on the TX4b .. works too. :-)
..other schematics ad an additional trogger tube for each nixie
cathode..the effort pretty much explodes...
Hope someone can help with some hints or links.
Regards,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583
info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741
An acquaintenance of mine, in the BBS world, has a zero-cost dialup service
for anyone wishing to use it. Thought I'd spread the word.
For dialup details, follow the link. I believe he said there are ninety
nodes and may see five used at any given time.
Ref: https://2600.network
Enjoy,
Daniel
sysop | Air & Wave BBS
finger | calcmandan(a)bbs.erb.pw
> Paul Koning <paulkoning(a)comcast.net> wrote:
> On the other hand, the even more obscure DECnet/8 was found a couple
> of years ago. Its main limitation ....
Besides being Phase-I, DECnet/8 is not a "complete" implementation. The
only application provided is a console to console talk program that can only
talk to other PDP-8 nodes. There's no FAL, CTERM/RTERM, NFT, NCP, or any of
the other things you might expect. I think DEC expected customers to write
their own RTS/8 and DECnet-8 applications.
Bob
I learned tonight that someone cleaned out my storage unit, and part of their haul was a couple of cartons of DEC boards. I haven't dug up the itemized list but in there were several QBus VAX memory boards, a graphics adapter, a microVAX III board set, a couple of RQDX boards, both QBus and Unibus serial boards, Unibus SDI board sets, a BA123 cabinet, tk70 controllers, a couple of Ethernet boards...
And a Mentec/93.
If anyone unfamiliar approaches you about selling a big stash of DEC, please get all the info you can and call the police.
Thank you.
Doc
On Mon, 2 Mar 2026, Fred Cisin wrote:
> With a couple thousands I mean several thousands. And drawerS and
cabinetS
> because we got several cabinetS with drawerS with our machine. One
drawer
> contains three trays that hold about 2000 cards each.
> Download our files and count the card yourself!
Download from where?
As a student at UC Berkeley (1967-1971), I had a part-time job at the Computer Center, which ran a CDC 6400 under SCOPE. We punched cards, transferred them to magnetic tape, and used UPDATE to maintain logical decks. I personally used this technology while working on CAL SNOBOL and CAL TSS. Once we got CAL TSS far enough along to support development (on a second CDC 6400), we switched to Teletypes (a mixture of Model 33’s and Model 35’s). I still have source code for CAL SNOBOL because of archivists at U. of Arizona and U. of Texas, but most of the source code for CAL TSS was lost (listings survive).
Paul McJones
https://www.mcjones.org/CAL_SNOBOL/https://caltss.computerhistory.org/
Hello,
I bought a Wang 600 in unknown operating condition, but it looked to be
complete and undamaged. Unfortunately, the shipper used a "professional"
shipping service that wrapped this calculator in a single layer of bubble
wrap, put it in a single wall box, and filled the rest of the space with
packing peanuts. The result was predictable. The rear and sides of the
molded ABS case were completely shattered, the rear mounted fan was knocked
off, the housing bent, and a fan blade broken off. Fortunately (if that's
the right word) the chassis, cards, keyboard, and display all seem intact.
To try to assess the extent of the damage, I would like to complete the
removal of the plastic case but do not see how it is fastened to the
chassis. Can anyone help? Also, any troubleshooting info would be
appreciated! I already have the schematics, but I probably won't be needing
them until I do some inspections and basic checks.
Thanks,
Stan
