Suggestions & Advice for (much) older PiDP-11

[sunnybo...@gmail.com]

I just restarted my PiDP-11 after being turned off for several years. I bought a glass front rack case and installed my PiDP8 and PiDP11 (plus other systems) in it. Both 8 and 11 were running and working perfectly when turned off (properly).

Finally after several years and another equipment reshuffle, the glass rack is back where I can run it. The PiDP11 came up immediately and is running "just fine".

 The PiDP8 would not start - turned out to be a corrupted SD card... so corrupted it refused all attempts at writing a new Raspbien (verify failed multiple times). I got another SD card, wrote the most recent Raspbien for that hardware (Pi3B+, 64bit) and then installed the latest PiDP8i software according to current documentation. It now works perfectly. Of course I lost all the FORTRAN programs that were on it, but when the SD card is corrupted, that just happens.

HOWEVER - my PiDP11 is running fine. I boot BSD2.11 and have a LOT of FORTRAN, assembler and C programs that run on it. I even had it running a HTTPD server that was ported to the internet. BUT - everything on that system is dated 2018. 

The problem is the version of Raspbien on the PiDP11 is so old (2018) that it won't update anymore. "sudo apt update" simply fails with errors finding repos. 

The solution is to write the latest Raspbien for the Pi3B+ (64 bit) just like I did for the PiDP8. I can then install one the latest version of Oscar's PiDP11 software, or perhaps even a newer fork as I've been following here.

MY PROBLEM, and my request is twofold. First, is there a guide somewhere on how to copy all my programs off the current BSD2.11 OS on the running PiDP11 before I eliminate it in a rewrite? (and how to get them back on). I know I did it before, but that was back in 2018 and I didn't write it all down, and am now old enough that I can't remember where the info was. Any assistance would be welcome.

And for advice, is it best to start with Oscar's PiDP11 repo or another one? I've tried to follow the whole "patch BSD2.11" threads, but am frankly lost. I never did patch my  BSD2.11 when it was running in 2018, even though patches were being made at the time. I did follow threads and was able to get external networking running with BSD (hence the HTTPD server working) but I suspect things have changed there as well. I remember I had to use wired ethernet at the time as WIFI bridging simply didn't work.

Anyway, thanks in advance for any assistance/advice. Mostly I need to be able to get my source files OFF the current BSD2.11 onto another computer so I can reverse the process once the new PiDP11/BSD2.11 is built.

Thanks,

-R

[terri-...@glaver.org]

On Wednesday, March 11, 2026 at 1:08:31 AM UTC-4 sunnybo...@gmail.com wrote:

 The PiDP8 would not start - turned out to be a corrupted SD card... so corrupted it refused all attempts at writing a new Raspbien (verify failed multiple times). I got another SD card, wrote the most recent Raspbien for that hardware (Pi3B+, 64bit) and then installed the latest PiDP8i software according to current documentation. It now works perfectly. Of course I lost all the FORTRAN programs that were on it, but when the SD card is corrupted, that just happens.

Most SD cards aren't really intended for write-intensive applications. About the best you can do is use one of the name brand ones intended for video recording (being written over and over), although the PiDPs tend to concentrate their writes on a smaller area of the card. If you have a Pi 5, you can use a "backwards" NVMe adapter like the Pimoroni NVMe BASE (you can't use the official Pi 5 NVMe NAT+ because the PiDP *IS* the hat). If you have an older Pi, the Raspberry Pi people have come up with a high-endurance USB stick.

But as we learned from head crashes and other problems "back in the day" - backups, backups, backups.

HOWEVER - my PiDP11 is running fine. I boot BSD2.11 and have a LOT of FORTRAN, assembler and C programs that run on it. I even had it running a HTTPD server that was ported to the internet. BUT - everything on that system is dated 2018. 

The problem is the version of Raspbien on the PiDP11 is so old (2018) that it won't update anymore. "sudo apt update" simply fails with errors finding repos. 

You probably want Raspbian Bookworm (currently called "Legacy" in the Raspberry Pi Imager and manual download links).
 

The solution is to write the latest Raspbien for the Pi3B+ (64 bit) just like I did for the PiDP8. I can then install one the latest version of Oscar's PiDP11 software, or perhaps even a newer fork as I've been following here.

MY PROBLEM, and my request is twofold. First, is there a guide somewhere on how to copy all my programs off the current BSD2.11 OS on the running PiDP11 before I eliminate it in a rewrite? (and how to get them back on). I know I did it before, but that was back in 2018 and I didn't write it all down, and am now old enough that I can't remember where the info was. Any assistance would be welcome.

Assuming your current system has the operating systems in /opt/pidp11/systems, you should just be able to write a new SD card, ignore the part about installing PDP-11 operating systems, and copy your existing /opt/pidp11/systems directory tree over. The best way to go about that depends on what types of I/O gizmos you have hanging around. Probably the easiest is to plug a USB stick into your existing running older Pi install and copy the systems tree to the USB stick, then the reverse with the new SD card. You don't want to overwrite your existing install since it works and has your files - just grab a new SD card and start fresh. Your install may be so old that it uses something other than the current systems layout, in which case just do the install (including PDP-11 operating systems) and then just move your boot.ini and disk image(s) into the appropriate place in the new systems tree

And for advice, is it best to start with Oscar's PiDP11 repo or another one? I've tried to follow the whole "patch BSD2.11" threads, but am frankly lost. I never did patch my  BSD2.11 when it was running in 2018, even though patches were being made at the time. I did follow threads and was able to get external networking running with BSD (hence the HTTPD server working) but I suspect things have changed there as well. I remember I had to use wired ethernet at the time as WIFI bridging simply didn't work.

You can either use Oscar's official https://github.com/obsolescence/pidp11 repo or my bugfix + features one (which will eventually merge back into Oscar's repo) https://github.com/Terri-Kennedy/pidp11. If you use mine, you MUST select the "compile from source" as the binaries haven't been updated yet.

2.11BSD is still getting patches (499 came out this January). Without knowing what patchlevel you're at (look at /VERSION to see) I can't say if it would be worthwhile to update now or wait. There are known issues with some of the 2.11BSD images floating around - some have incompletely applied patches. The Covello 482 (which is what the install script offers) is missing at least some of the post-install tasks from 482, and there was an older partially-failed patch installation.

I have a patch 499 which runs on emulated RM05s and a TU77. I believe Johnny Billquist has a 499 running with emulated MSCP disks and unknown tape. Contact either of us offline if interested.

WiFi bridging is better in newer Raspberry Pi OS, but still a lot more difficult to set up than a simple wired connection. 

Anyway, thanks in advance for any assistance/advice. Mostly I need to be able to get my source files OFF the current BSD2.11 onto another computer so I can reverse the process once the new PiDP11/BSD2.11 is built.

I suggest you keep all of your local code in a dedicated directory tree so you can simply tar it up and move it to a new installation.  

Here's my PiDP-11 innards with an Pi 5 + NVMe + 4 real serial ports (and yes, the back cover does fit on - barely - even without an extender):

[sunnybo...@gmail.com]

Thanks Terry!

I see a couple of options going forward with Raspbien; the easiest is to just pull the SD card and write the latest 64 bit version for the Pi3B+ that's in the PiDP11. That's what I did with my PiDP-8 when it's SD card corrupted and I had to find another. I also need to stop the PiDP-11 and open it up to access the Pi3B+ inside.

The big issue now is if I get another SD card, it WILL be bigger though I doubt I really need the size - just economy of amazon. That would allow me to save the current SD card intact. Sadly, I see none of the NVME boards are compatible with a Raspberry Pi 3B+, and I really don't want to consider upgrading at this time. The bottom hat NVME I'm using now is only for Pi 5, and I really can't afford that right now.

As for BSD 2.11, I have a few immediate options. I'm very familiar with using unix, so am already using tar to make a copy of the /opt/pidp11 directory, and I'll do the same with just the pidp11/systems directory. I plan to beam them via winscp to my devel PC and raid storage for safekeeping. That should keep a working copy of "what I  have now". I think I'll beam just the /opt/pidp11/systems/211bsd directory as well, as that's the files there that really matter. 

I also think I'll just go with your distro for now. Sounds like fun seeing it all build. 

As for my current BSD2.11, I can't seem to locate  /VERSION. When I boot things manually, I see "REALCONS build January 2019", so it's old. Booting BSD 2.11 it says "2.11 BSD UNIX #19: Sun Jun 17 16:44:43 PDT 2012", then "root@pdp11:/usr/src/sys/ZEKE". ... hang on... GOT IT (maintenance mode, saw file VERSION):

Current Patch Level: 448
Date: January 5, 2010

So it is indeed old!

The best thing would be if someone with a working "fully patched" version of BSD would simply tar the ./systems/211bsd directory and make that available. :-)

Again, thanks!

-R

[sunnybo...@gmail.com]

Hi Terry,

OK. Quick update... I was able to rewrite the PiDP11's 32GB SD card with a newer 64bit Raspbien (Trixie), same as my PiDP8 earlier this week.

AGAIN (this is very annoying), even after changing user/password and adding SSID/password, the system would not come up 'headless'. Same issue as with the PiDP8 rebuild. I had to (again) connect a keyboard/mouse (mini version) and mini HDMI screen to do ANYTHING. I had also had to enter EVERYTHING from scratch to get the system into a bootable state, and (worse, IMO) SSH terminal is by default OFF, as is VNC but I expect that. This is perhaps the worst build of an OS for Raspberry Pi I've ever experienced.

Anyway, now at a stable updated Raspbien, ready to install PiDP11 software. I'm going to go with your version because... why not? I'll let you know how it goes. FYI I'm not using 'pi' as my username. I'm following your instructions at this very moment... :-)

-R

[sunnybo...@gmail.com]

Terry,

It did give me a warning about Trixie, but I went ahead anyway because... (again) why not? At a minimum it will supply you with some feedback on how it works with Trixie.

For the install script, I answered yes to everything except "compile from source". So far it's doing well; completed compile from source, now installing the operating systems; vt52, Chase Covello's 2.11BSD; Johnny Billquist's RSX; and DONE. and reboot.

The front panel lit up after boot; my front panel switches are set to boot BSD2.11. Opening a VT52 terminal on a VNC connection shows it's at the boot prompt for BSD. I'm booting up to multi-user mode (it's SLOW on a Pi3B+) and logging in as root. VERSION says "Current Patch Level 451 December 22, 2018". Still newer than what I was using!

Looks great, and seems to be working perfectly at this point. 

Cheers,

-R

[terri-...@glaver.org]

On Wednesday, March 11, 2026 at 2:22:17 PM UTC-4 sunnybo...@gmail.com wrote:

Hi Terry,

OK. Quick update... I was able to rewrite the PiDP11's 32GB SD card with a newer 64bit Raspbien (Trixie), same as my PiDP8 earlier this week.

Remember, Trixie support is largely untested and Raspberry Pi OS / Debian does tend to break things the PiDPs need. 

AGAIN (this is very annoying), even after changing user/password and adding SSID/password, the system would not come up 'headless'. Same issue as with the PiDP8 rebuild. I had to (again) connect a keyboard/mouse (mini version) and mini HDMI screen to do ANYTHING. I had also had to enter EVERYTHING from scratch to get the system into a bootable state, and (worse, IMO) SSH terminal is by default OFF, as is VNC but I expect that. This is perhaps the worst build of an OS for Raspberry Pi I've ever experienced.

Did you use the Raspberry Pi Imager? It Gives you the option to enable SSH, etc:

https://www.raspberrypi.com/documentation/computers/getting-started.html#raspberry-pi-imager

The default desktop is Wayland and the default VNC viewer is WayVNC. If you want to switch to X11, you need to disable VNC, switch to X11, reboot and re-enable VNC (which gets you RealVNC). If you skip a step, you get an unresponsive WayVNC showing at an empty desktop because the desktop has moved to X11.

WiFi and the PiDP software can be made to work, but cabled Ethernet is a lot easier, as long as you don't care that 2BSD and the Pi can't ping or otherwise communicate with each other.

Anyway, now at a stable updated Raspbien, ready to install PiDP11 software. I'm going to go with your version because... why not? I'll let you know how it goes. FYI I'm not using 'pi' as my username. I'm following your instructions at this very moment... :-)

Ok. 

[terri-...@glaver.org]

On Wednesday, March 11, 2026 at 12:36:34 PM UTC-4 sunnybo...@gmail.com wrote:

The big issue now is if I get another SD card, it WILL be bigger though I doubt I really need the size - just economy of amazon. That would allow me to save the current SD card intact. Sadly, I see none of the NVME boards are compatible with a Raspberry Pi 3B+, and I really don't want to consider upgrading at this time. The bottom hat NVME I'm using now is only for Pi 5, and I really can't afford that right now.

The NVMe HAT+ / BASE only work with the Pi 5 because the older Pi models don't expose a PCIe lane, which the NVMe drive needs.

Maybe keep a USB drive installed in the Pi and regularly back up your whole 2BSD virtual disk(s) and boot.ini to it, in case the SD card bites the dust. You'll need to open the case to pull the SD card out if it fails, anyway. Just be careful with the boot order in raspi-config - you want it to try the SD card before trying (and failing) to boot from the USB drive.

 

The best thing would be if someone with a working "fully patched" version of BSD would simply tar the ./systems/211bsd directory and make that available. :-)

I'd suggest holding off for a bit unless Johnny has a truly generic 499 disk image. Mine has a number of changes and I'm not sure I'd be able to revert all of them from memory. 

[Johnny Billquist]

Working on that canonical 2.11BSD image... :-)

Johnny

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Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: b...@softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol

[sunnybo...@gmail.com]

Johnny,

Very much looking forward to it! I'm not averse to applying patches to a known good version, just where I was compared to where I needed to be was almost a vertical cliff up updates. Thanks to the rewrite of my SD card with "the latest" (for a Pi3b+), it closer to being achievable.

BSD 2.11 is among the first operating systems I used (the first being CDC Cyber punch cards, the second Honeywell Multics), it's always been one of my favorites. In the long ago days of 'unix wars', I was firmly on the 'not system V'  group. Most of my work was done on Solaris on Sun boxes, so definitely in the BSD camp. It's only recently (last 10 years) that the last of my Solaris servers moved over to Ubuntu, where they are today.

[Manfred Koethe]

Another storage option is the Transcend ESD310, which is a real SSD in the form factor of an USB stick. It has a USB A and a USB C connector. Besides being robust, it is also very fast. I use it on my PiDP "CASTOR" (which is currently offline due to travel).

If using SD Cards, it is advisable to use fast large capacity cards. Even it sounds like a waste, but *good* brand-name cards typically have wear-leveling controllers, which utilizing the excess capacity for a good life endurance.

Manfred