9 Mar
2026
9 Mar
'26
8:18 a.m.
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)
10 Mar
10 Mar
1:05 a.m.
Thank you very much for sharing your notes!
How did you get that working?
Do you have the manual or did you manage it through trial and error?
Ulli.
Am Di., 10. März 2026 um 04:56 Uhr schrieb johnforecast--- via cctalk <
cctalk(a)classiccmp.org>gt;:
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)
7:21 a.m.
Once I took at look at the filenames and some of the file contents, it was pretty obvious
that this was based on the DECnet-11M code base. I was project leader for DECnet-11M+
Phase III, so that made it a lot easier.
John.
On Mar 10, 2026, at 4:05 AM, Hans-Ulrich Hölscher
<vaxorcist(a)googlemail.com> wrote:
Thank you very much for sharing your notes!
How did you get that working?
Do you have the manual or did you manage it through trial and error?
Ulli.
Am Di., 10. März 2026 um 04:56 Uhr schrieb johnforecast--- via cctalk
<cctalk(a)classiccmp.org <mailto:cctalk@classiccmp.org>>:
> 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)
>
1:37 a.m.
Thank you! This is so cool, I want to get decnet running on my pdt11/150 and connect it to
my rsx11 system.
I wonder if it can support sync serial options so I can run it at 19200 baud on the
"modem" port on the pdt.
On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk
<cctalk(a)classiccmp.org> wrote:
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)
2:10 a.m.
I'm trying to run DECnet-RT from:
RT-11FB V05.03
Booted from DL0:RT11FB
which was generated with:
5. Do you want device time-out support (N)? Y
but I get:
.ASSIGN SY NT
.r ncp
?NCP-U-No device timeout support in monitor
My generated answer files contains the line:
SETT TIM$IT .;Device time out
Do you have any idea what might have gone wrong?
Ulli.
Am Di., 10. März 2026 um 09:37 Uhr schrieb Christopher Zach via cctalk <
cctalk(a)classiccmp.org>gt;:
Thank you! This is so cool, I want to get decnet
running on my pdt11/150
and connect it to my rsx11 system.
I wonder if it can support sync serial options so I can run it at 19200
baud on the "modem" port on the pdt.
On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk <
cctalk(a)classiccmp.org> wrote:
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)
7:54 a.m.
That looks like you’re still running the distributed monitor. SYSGEN will generate files
of the form RT11FB.SYG and DL.SYG etc. You are expected to copy or rename those files to
RT11FB.SYS etc, hook the bootstrap with:
.COPY/BOOT dd:RT11FB.SYS dd:
and reboot.
John.
On Mar 10, 2026, at 5:10 AM, Hans-Ulrich Hölscher via
cctalk <cctalk(a)classiccmp.org> wrote:
I'm trying to run DECnet-RT from:
RT-11FB V05.03
Booted from DL0:RT11FB
which was generated with:
5. Do you want device time-out support (N)? Y
but I get:
.ASSIGN SY NT
.r ncp
?NCP-U-No device timeout support in monitor
My generated answer files contains the line:
SETT TIM$IT .;Device time out
Do you have any idea what might have gone wrong?
Ulli.
Am Di., 10. März 2026 um 09:37 Uhr schrieb Christopher Zach via cctalk <
cctalk(a)classiccmp.org>gt;:
> Thank you! This is so cool, I want to get decnet running on my pdt11/150
> and connect it to my rsx11 system.
>
> I wonder if it can support sync serial options so I can run it at 19200
> baud on the "modem" port on the pdt.
>
> On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk <
> cctalk(a)classiccmp.org> wrote:
>> 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)
>>
>
9:51 a.m.
Or boot them to see if they work first
On March 10, 2026 2:54:36 PM GMT, johnforecast--- via cctalk <cctalk(a)classiccmp.org>
wrote:
That looks like you’re still running the distributed
monitor. SYSGEN will generate files of the form RT11FB.SYG and DL.SYG etc. You are
expected to copy or rename those files to RT11FB.SYS etc, hook the bootstrap with:
.COPY/BOOT dd:RT11FB.SYS dd:
and reboot.
John.
On Mar 10, 2026, at 5:10 AM, Hans-Ulrich Hölscher
via cctalk <cctalk(a)classiccmp.org> wrote:
I'm trying to run DECnet-RT from:
RT-11FB V05.03
Booted from DL0:RT11FB
which was generated with:
5. Do you want device time-out support (N)? Y
but I get:
.ASSIGN SY NT
.r ncp
?NCP-U-No device timeout support in monitor
My generated answer files contains the line:
SETT TIM$IT .;Device time out
Do you have any idea what might have gone wrong?
Ulli.
Am Di., 10. März 2026 um 09:37 Uhr schrieb Christopher Zach via cctalk <
cctalk(a)classiccmp.org>gt;:
> Thank you! This is so cool, I want to get decnet running on my pdt11/150
> and connect it to my rsx11 system.
>
> I wonder if it can support sync serial options so I can run it at 19200
> baud on the "modem" port on the pdt.
>
> On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk <
> cctalk(a)classiccmp.org> wrote:
>> 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)
>>
>
6:39 a.m.
Chris, yes! This situation is very lucrative for the humble PDT and was actually why I
asked about DECnet-RT to begin with!
Couple all this with a 10MB TU58 setup and we’re off to the native diskless tiny PDP-11
network workstation races! I’ve got the latter piece going on my 150 and also used it to
assemble the PD floppy driver from an older release under RT-11 5.07, no prob. So now we
have all the individual pieces working, just a matter of integrating.
Thanks, John, for posting results of your efforts in vetting the newly recovered DECnet
bits.
—jake
On Mar 10, 2026, at 04:37, Christopher Zach via cctalk
<cctalk(a)classiccmp.org> wrote:
Thank you! This is so cool, I want to get decnet running on my pdt11/150 and connect it
to my rsx11 system.
I wonder if it can support sync serial options so I can run it at 19200 baud on the
"modem" port on the pdt.
> On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk
<cctalk(a)classiccmp.org> wrote:
> 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)
>
7:49 a.m.
As configured it will use the “Terminal 1” port on a PDT-11/150. I doubt it will support
sync serial - it looks like the standard DL-11 driver from RSX.
John.
On Mar 10, 2026, at 4:37 AM, Christopher Zach via
cctalk <cctalk(a)classiccmp.org> wrote:
Thank you! This is so cool, I want to get decnet running on my pdt11/150 and connect it
to my rsx11 system.
I wonder if it can support sync serial options so I can run it at 19200 baud on the
"modem" port on the pdt.
On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk
<cctalk(a)classiccmp.org> wrote:
> 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)
>
9:12 a.m.
Sorry to trouble you again.
NCP starts fine now, but:
.r ncp
NCP>SET SYSTEM
?NCP-F-Set failed, operation failure
CX: device not installed
NCP>
I checked the simh setup:
sim> sh dli
DLI address=17776500-17776507, vector=300-304*, BR4, lines=1
attached to Connect=127.0.0.1:4200;notelnet, disconnected
sim> sh dlo
DLO
8B, dataset, no logging
sim>
Does DLI have to be connected?
Ulli.
Am Di., 10. März 2026 um 16:37 Uhr schrieb johnforecast--- via cctalk <
cctalk(a)classiccmp.org>gt;:
As configured it will use the “Terminal 1” port on a
PDT-11/150. I doubt
it will support sync serial - it looks like the standard DL-11 driver from
RSX.
John.
On Mar 10, 2026, at 4:37 AM, Christopher Zach via
cctalk <
cctalk(a)classiccmp.org> wrote:
Thank you! This is so cool, I want to get decnet running on my pdt11/150
and connect it to my rsx11 system.
I wonder if it can support sync serial options so I can run it at 19200
baud on the "modem" port on the pdt.
On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk <
cctalk(a)classiccmp.org> wrote:
> 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)
>
11:06 a.m.
CX.SYS should have been copied over from RX0810.IMG. After “SET SYSTEM” you should have
the following memory layout:
.sh mem
Address Module Words
------- ------ -----
160000 IOPAGE 4096.
157242 VM 175.
135440 RMON 4545.
113420 CX 4616.
076374 NS 3338.
070274 CP 1568.
065244 VL 780.
001000 ..BG.. 13394.
and after “SET EXEC STA ON”:
.sh mem
Address Module Words
------- ------ -----
160000 IOPAGE 4096.
157242 VM 175.
135440 RMON 4545.
113420 CX 4616.
076374 NS 3338.
070274 CP 1568.
065244 VL 780.
050222 F 3337.
001000 ..BG.. 10057.
John.
On Mar 10, 2026, at 12:12 PM, Hans-Ulrich Hölscher
<vaxorcist(a)googlemail.com> wrote:
Sorry to trouble you again.
NCP starts fine now, but:
.r ncp
NCP>SET SYSTEM
?NCP-F-Set failed, operation failure
CX: device not installed
NCP>
I checked the simh setup:
sim> sh dli
DLI address=17776500-17776507, vector=300-304*, BR4, lines=1
attached to Connect=127.0.0.1:4200;notelnet, disconnected
sim> sh dlo
DLO
8B, dataset, no logging
sim>
Does DLI have to be connected?
Ulli.
Am Di., 10. März 2026 um 16:37 Uhr schrieb johnforecast--- via cctalk
<cctalk(a)classiccmp.org <mailto:cctalk@classiccmp.org>>:
> As configured it will use the “Terminal 1” port on a PDT-11/150. I doubt it will
support sync serial - it looks like the standard DL-11 driver from RSX.
>
> John.
>
>
> > On Mar 10, 2026, at 4:37 AM, Christopher Zach via cctalk
<cctalk(a)classiccmp.org <mailto:cctalk@classiccmp.org>> wrote:
> >
> > Thank you! This is so cool, I want to get decnet running on my pdt11/150 and
connect it to my rsx11 system.
> >
> > I wonder if it can support sync serial options so I can run it at 19200 baud on
the "modem" port on the pdt.
> >
> > On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk
<cctalk(a)classiccmp.org <mailto:cctalk@classiccmp.org>> wrote:
> >> 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)
> >>
>
9:52 a.m.
Sp 176500/300.
On March 10, 2026 2:49:06 PM GMT, johnforecast--- via cctalk <cctalk(a)classiccmp.org>
wrote:
As configured it will use the “Terminal 1” port on a
PDT-11/150. I doubt it will support sync serial - it looks like the standard DL-11 driver
from RSX.
John.
On Mar 10, 2026, at 4:37 AM, Christopher Zach via
cctalk <cctalk(a)classiccmp.org> wrote:
Thank you! This is so cool, I want to get decnet running on my pdt11/150 and connect it
to my rsx11 system.
I wonder if it can support sync serial options so I can run it at 19200 baud on the
"modem" port on the pdt.
On March 9, 2026 4:18:55 PM GMT+01:00, johnforecast--- via cctalk
<cctalk(a)classiccmp.org> wrote:
> 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)
>
8:03 a.m.
On Mar 10, 2026, at 4:37 AM, Christopher Zach via
cctalk <cctalk(a)classiccmp.org> wrote:
Thank you! This is so cool, I want to get decnet running on my pdt11/150 and connect it
to my rsx11 system.
I wonder if it can support sync serial options so I can run it at 19200 baud on the
"modem" port on the pdt.
Is the PDT port a USART? In any case you could treat it as a UART and do DDCMP over that,
it works fine (DDCMP handles either sync or async serial lines, and even other stuff like
the PCL-11 if you happen to have one).
The Pro modem port is definitely a USART, and I have used it in both modes. Unfortunately
it has a tiny FIFO.
paul
12:11 p.m.
On Mar 9, 2026, at 11:18 AM, johnforecast--- via
cctalk <cctalk(a)classiccmp.org> wrote:
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.
...
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)
So there is TLK but not the matching server (LSN)? It should talk to RSTS, I assume. And
PyDECnet has a LSN also.
paul
2:14 p.m.
On Mar 10, 2026, at 3:11 PM, Paul Koning via cctalk
<cctalk(a)classiccmp.org> wrote:
According to the object definitions, it looks like TLK is both client and server.
John.
On Mar 9, 2026, at 11:18 AM, johnforecast--- via
cctalk <cctalk(a)classiccmp.org> wrote:
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.
...
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)
So there is TLK but not the matching server (LSN)? It should talk to RSTS, I assume.
And PyDECnet has a LSN also.
paul
11 Mar
11 Mar
4:08 a.m.
You've probably noticed that I'm not very familiar with RT-11; my operating
system "home" is VMS.
I've got three more questions, two for SIMH (but related to DECnet-RT) and
one for RT-11 / DECnet-RT.
- I am familiar with connecting two SIMH VAX instances for asynchronous
serial DDCMP, which looks like:
VAX A:
SET DZ ENABLE
SET DZ LINES=4
ATT DZ LINE=0,44012,CONNECT=127.0.0.1:44021
VAX B:
SET DZ ENABLE
SET DZ LINES=4
ATT DZ LINE=0,44021,CONNECT=127.0.0.1:44012
The first question is how to configure a SIMH PDP-11 running DECnet-RT and
a SIMH VAX running DECnet-VAX over asynchronous serial DDCMP.
The second question is how to configure two SIMH PDP-11s running DECnet-RT
over asynchronous serial DDCMP.
The third question is can I start e.g. FAL and continue interactive work,
e.g. using RVT?
I hope I'm not being too pushy - Thanks a lot for your valuable continuous
help!
Ulli.
Am Mi., 11. März 2026 um 07:52 Uhr schrieb johnforecast--- via cctalk <
cctalk(a)classiccmp.org>gt;:
RSTS, I assume. And PyDECnet has a LSN also.
On Mar 10, 2026, at 3:11 PM, Paul Koning via
cctalk <
cctalk(a)classiccmp.org> wrote:
> On Mar 9, 2026, at 11:18 AM, johnforecast--- via cctalk <
cctalk(a)classiccmp.org> wrote:
>
> 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.
> ...
> 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)
So there is TLK but not the matching server (LSN)? It should talk to
paul
According to the object definitions, it looks like TLK is both client and
server.
John.
8:05 a.m.
On Mar 11, 2026, at 7:08 AM, Hans-Ulrich Hölscher
<vaxorcist(a)googlemail.com> wrote:
You've probably noticed that I'm not very familiar with RT-11; my operating
system "home" is VMS.
I've got three more questions, two for SIMH (but related to DECnet-RT) and one for
RT-11 / DECnet-RT.
- I am familiar with connecting two SIMH VAX instances for asynchronous serial DDCMP,
which looks like:
VAX A:
SET DZ ENABLE
SET DZ LINES=4
ATT DZ LINE=0,44012,CONNECT=127.0.0.1:44021 <http://127.0.0.1:44021/>
VAX B:
SET DZ ENABLE
SET DZ LINES=4
ATT DZ LINE=0,44021,CONNECT=127.0.0.1:44012 <http://127.0.0.1:44012/>
The first question is how to configure a SIMH PDP-11 running DECnet-RT and a SIMH VAX
running DECnet-VAX over asynchronous serial DDCMP.
You should be able to to set it up similar to your VAXes, just use DLI/DLO as the devices
for DECnet-RT as I described in my notes. Make sure both ends have the same “;notelnet”
setting.
The second question is how to configure two SIMH
PDP-11s running DECnet-RT over asynchronous serial DDCMP.
Same as above except both ends will use DLI/DLO.
The third question is can I start e.g. FAL and
continue interactive work, e.g. using RVT?
No. As I said the images we have are for an unmapped system so once you’ve loaded FAL
there’s very little memory left (probably < 1KB). If we could find a full kit it would
probably at least 124KW and probably allow multiple jobs, but that’s just a guess!
I hope I'm not being too pushy - Thanks a lot for
your valuable continuous help!
No problem,. I’m glad the notes were useful.
John.
Ulli.
Am Mi., 11. März 2026 um 07:52 Uhr schrieb johnforecast--- via cctalk
<cctalk(a)classiccmp.org <mailto:cctalk@classiccmp.org>>:
>
> > On Mar 10, 2026, at 3:11 PM, Paul Koning via cctalk <cctalk(a)classiccmp.org
<mailto:cctalk@classiccmp.org>> wrote:
> >
> >
> >
> >> On Mar 9, 2026, at 11:18 AM, johnforecast--- via cctalk
<cctalk(a)classiccmp.org <mailto:cctalk@classiccmp.org>> wrote:
> >>
> >> 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.
> >> ...
> >> 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)
> >
> > So there is TLK but not the matching server (LSN)? It should talk to RSTS, I
assume. And PyDECnet has a LSN also.
> >
> > paul
> >
>
> According to the object definitions, it looks like TLK is both client and server.
>
> John.
>
1
days inactive
3
days old
16 comments
5 participants
participants (5)
-
Christopher Zach -
Hans-Ulrich Hölscher -
Jacob Ritorto -
johnforecast＠comcast.net -
Paul Koning