Waiting for console Telnet connection

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Paulo Rebordão

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Mar 30, 2026, 6:49:15 AM (5 days ago) Mar 30
to [PiDP-11]
Another issue...

When booting RSX, I get the message above and the boot stops there, as I'm unable to logon to RSX.

Something is missing?

Johnny Billquist

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Mar 30, 2026, 7:50:19 AM (5 days ago) Mar 30
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Never seen that, but that sounds like something on the simh side. I
guess you have the console associated with a telnet port. Have you tried
connecting to that, and see what happens?

Johnny
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John D. Bruner

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Mar 30, 2026, 11:01:53 AM (5 days ago) Mar 30
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The basic idea of having the PDP-11/70 console available over telnet is that it separates the SIMH interaction from the interaction with (in your case) RSX-11M. For example, you could put them in separate "screen" sessions, and typing ^E to RSX-11M won't cause simh to drop into its command prompt. If that's what you want, then look for "set console" commands in the boot script to determine what telnet port it is using. You can connect to it with

telnet localhost PORT

If the console is buffered, then you'll see the output that was already generated.

Alternatively, if you would prefer to keep them in the same place, you can delete those commands from the boot script.

--John
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Manfred Koethe

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Mar 31, 2026, 3:10:39 AM (4 days ago) Mar 31
to [PiDP-11]
If you use Johnny's RSX-11M-Plus at /opt/pidp11/systems/rsx11bq
then look into file boot.ini
In the block:
-----------
; under SimH 4, "throttling" results in a disturbed "idle pattern"
;set nothrottle
set noidle
set throttle 50%
;set console telnet=10000
sho cpu
-----------
uncomment (remove the ";") the line ;set console telnet=10000
and restart SimHH and your PiDP

This should work.

Also, if you want to access the Ethernet out of RSX (DECnet or just IP), then you need to run the emulation with root privileges for now, or else you will not be able to connect to the Linux eth0.
I may have time later this week to find the right Capability settings, and in particular the right place to attach them, to make this problem going away. (The Capability settings currently in the kit are not effective for this, also I cannot speak for the other PDP operating systems besides RSX-11M-Plus at this time, but they are likely affected as well).

Manfred 

John D. Bruner

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Mar 31, 2026, 11:38:50 AM (4 days ago) Mar 31
to Manfred Koethe, [PiDP-11]
If you configure the console for telnet, you may also want to consider making it buffered, e.g.,

set console telnet=buffered

Accessing eth0 directly as non-root requires the CAP_NET_RAW and CAP_NET_ADMIN capabilities. You can give those to the client11 executable with

sudo setcap cap_net_raw,cap_net_admin+ep /opt/pidp11/bin/client11

(By specifying "ep" rather than "eip", any children that client11 creates (e.g., when you use the "!" command at the "simh" prompt) won't inherit the capabilities.)

--John




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