Latest PiDP-11 distribution

[Mike Katz]

Is the latest, up to date, PiDP-11 distribution on the Oscar's
obsolescence sight or is it some place else (github, etc)?

Thank you....

[terri-...@glaver.org]

Oscar's official development/distribution tree is at https://github.com/obsolescence/pidp11

My somewhat newer fork (which will be merged back into Oscar's main branch when I'm done) is at https://github.com/Terri-Kennedy/pidp11

[Curtis Smith (史國興)]

Might we assume that an announcement will be made on this group once your forked has been merged?

[terri-...@glaver.org]

On Wednesday, February 11, 2026 at 3:17:16 PM UTC-5 smi...@gmail.com wrote:

Might we assume that an announcement will be made on this group once your forked has been merged?

Yes. But that will be some time after I let Oscar know, since he's the only one with commit access to the official

repo.

In the meantime, feel free to use my fork. You'll get something that's a good deal better than the official repo,

with a number of BIG upcoming improvements. I'm working on an entirely new installer, as well as gathering

additional operating systems and documentation, some of which has never seen the light of day before.

When I switch my repo over to the new installer, I will definitely let everyone know. The old installer will remain

for a while after, in case issues show up with the new installer. 

[Manfred Koethe]

Terri,

About a month ago I installed a new headless system using your revised kit. I like the work you have done, but I have 

two comments and suggestions:

(1) The restriction to to the two latest versions of Raspberry OS, or the original Ubuntu, is too strong. Likewise the

restriction to Raspberry Pi hardware. I installed on an Odroid C2 running Ubuntu 20.04, that is the latest distribution

I could find for the Odroid. After I tricked your restrictions, everything installed and runs just fine (however headless

at this time).

(2) Your revised kit, and also the original kit from Oscar, has insufficient capability declarations to provide the level of

access to the ethernet controller (owned by the Linux...) that Johnny's BQTCP and also DECnet needs. Everything runs

just fine if pdp11control and pdp11 are started with root privileges (sudo).

I planned to help you, and I'm happy to do so, resolving both issues I listed above. I was just swamped . I have started

with the capabilities and will continue working on it this weekend. Relaxing the system requirements is just a matter 

of experimenting and testing, but I'm convinced there is no need to be so tight.  

Kind regards,

Manfred 

[terri-...@glaver.org]

On Thursday, February 12, 2026 at 11:50:31 PM UTC-5 Manfred Koethe wrote:

Terri,

About a month ago I installed a new headless system using your revised kit. I like the work you have done, but I have 

two comments and suggestions:

(1) The restriction to to the two latest versions of Raspberry OS, or the original Ubuntu, is too strong. Likewise the

restriction to Raspberry Pi hardware. I installed on an Odroid C2 running Ubuntu 20.04, that is the latest distribution

I could find for the Odroid. After I tricked your restrictions, everything installed and runs just fine (however headless

at this time).

A couple of comments:

This is the PiDP-11 software. Yes, you don't need to have the kit, but we do hope you have a Raspberry Pi 8-) 

There is a certain level of of support for Debian AMD64 (mostly untested).

The installer assumes the availability of the 'apt-get' command and certain packages, which may or may not

be available on other distros (I'm a FreeBSD user - my only use of non-embedded Linux is for these PiDP-11

systems, so I don't know the state of packaging on other distros). 

The problem is that each version of Raspberry Pi OS that comes along breaks stuff. New Pi models also break

stuff (different stuff). So it makes sense to concentrate efforts there. 

I can definitely add support for a "I know what I'm doing" environment variable that will cause the installer to

bypass all of the checks, print a "You break it, you bought it" warning, and proceed (or go kaboom).

(2) Your revised kit, and also the original kit from Oscar, has insufficient capability declarations to provide the level of

access to the ethernet controller (owned by the Linux...) that Johnny's BQTCP and also DECnet needs. Everything runs

just fine if pdp11control and pdp11 are started with root privileges (sudo).

Actually, Oscar's kit applies the permissions before replacing the executable, so they go away. If you select

compile from source (which is mandatory in my fork at the moment as the precompiled binaries haven't been

updated, it should do a:

sudo setcap cap_net_raw,cap_net_admin=eip /opt/pidp11/src/02.3_simh/4.x+realcons/bin-rpi/pdp11_realcons

If you answer yes to the "Configure PCAP permissions for current user?" question.

There's some other issues on non-Pi platforms which I need to look into. Raspberry Pi OS brings quite a 

few "creature comforts" beyond a regular  Debian install, and one of them is "we assume the user 'owns'

the system" which certainly isn't true of a multi-user Debian system on other hardware. So there's some

additional fiddling that needs to be done on non-Pi OS platforms.

I planned to help you, and I'm happy to do so, resolving both issues I listed above. I was just swamped . I have started

with the capabilities and will continue working on it this weekend. Relaxing the system requirements is just a matter 

of experimenting and testing, but I'm convinced there is no need to be so tight.  

You should definitely try the (incomplete) new installer, which you can get from:

https://www.glaver.org/PiDP-11/v2-install-test.sh

Once I had fixed most of the code issues, I started working on a complete rewrite of the installer, in

more of a "Classic DEC" flavor, complete with optional detailed explanations of each question. It

is perfectly safe to run on an existing installation, as long as you do not go past the:

This is your last chance to exit before installation proceeds. Do you
want to proceed or exit (proceed/exit, no default)?

question.

I can definitely add a "ignore all checks" override as I mentioned above. But that won't be in the 

existing installer.