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PiDP-11 system software
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bin 20180518 May 18, 2018
bootscripts set up boot images on google drive May 18, 2018
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src 20180518 May 18, 2018 Update Jan 22, 2019


A new version of the PiDP-11 software was released in January 2019.

Download the manual at and follow the instructions on page 11

This repository will remain online for a while, but you are recommended to use the above installation!



Important: github struggles with large binary images. So, do everything as per below. Then, download the contents of the bootscripts directory (OS disk images and boot scripts) from this Google Drive file:


  • expect updates of the pidp-11 software in the coming months
  • you do not need to have the PiDP-11 hardware, it'll run fine without. Just no lights and switches.

Install instructions:

  • make sure your Pi is connected to the internet during install, pull the pidp11 repository,
  • create a 'pidp11' directory into /opt, and copy the files inside the pidp11 clone directory into /opt/pidp11/,
  • run sudo ./ in /opt/pidp11/install/,
  • reboot
  • copy the contents of the above ZIP file into the bootscripts directory. It's easiest to download the file onto a USB stick from your laptop, then copy from the USB stick into the Pi.

After reboot, you should find yourself booting RSX-11M+. See detailed instructions at the end of this file.

NOTE: If you have your Pi booting into the GUI, you need to open a terminal in the GUI and run ~/ to grab the terminal of the already running PDP-11. However, if you configure the Pi to boot into the CLI, the PDP-11 comes up straight away. Which is nicer.

Using the PiDP-11, first steps:

To exit the PDP-11 (simh): CTRL-E, exit. To restart the PDP-11, see next section

To leave whilst keeping the PDP-11 running: CTRL-A, then d. Then, to return to the running PDP-11: ~/

Restarting with various boot options:

If the PiDP-11 front panel hardware is attached: select a boot script using one of the SR switches (1-21, not 0) You can now restart the PDP-11 with /opt/pidp11/bin/

Without front panel hardware, simply use ./ 2 to run boot script 2, etc.

Currently installed operating systems:

The idea is that this gradually fills up with fully loaded operating systems, of course. For now:

SR switch/OS SR switch/OS SR switch/OS SR switch/OS SR switch/OS
1 - RSX-11M + 6 - Unix v6 11 - 16 - 21 - Nankervis
2 - BSD211 7 - Unix v7 12 - 17 - Collection of
3 - RT11 8 - 13 - 18 - 15 OSes
4 - RSTS v7 9 - 14 - 19 -
5 - 10 - 15 - 20 - Hill's Blinky

Also see for the current state of the System Collection.

Changing boot scripts & adding your own:

Simh boot scripts are saved in pidp11/bootscripts. The first digit(s) in the file name will determine which SR switch will activate the script at program start. The rest of the file name can be whatever description it needs, but the extension has to be .script.

The disk & tape images your configuration script require are by convention stored in the numbered subdirectories (0-21) of the bootscripts directory. Also by convention, backup copies are in a subdirectory in case you mess up a disk image and want to start afresh.

Step-by-step install instructions

In case you're not too familiar with Raspbian/Linux: First make sure you've got a working internet connection (googling will help you quickly). Then:

  • cd ~
  • git clone git:// // not git clone
  • sudo mkdir /opt/pidp11
  • cd ~/pidp11 // note - this is the downloaded copy in your home directory...
  • sudo cp -r * /opt/pidp11/ // copy to the /opt/pidp11 directory
  • cd /opt/pidp11/install
  • sudo ./
  • <See comments at the top of this page. Download the bootscript/disk image collection and place it all in /opt/pidp11/bootscripts>
  • sudo reboot

Various notes

  • An update, in the form of a user-friendly download-and-boot SD card image will be published soon (2 weeks or so max).
  • The /opt/pidp11/src directory contains all sources. The two scripts in there allow you to recompile the client and server.
  • quick bug fix: to boot unix v7, change "att rp0 disk0.hp" into "att rp0 ../bootscripts/disk0.hp" in the file /opt/pidp11/bootscripts/7_unix_v7.script. Sorry!
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