Build arbitrary media using simh and stuff developed for pidp8i project.

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William Cattey

Apr 21, 2020, 6:08:18 PM4/21/20
There are a couple threads about different people creating bootable media, some with hardware, and some operating in simulation in simh or other platforms.

This thread is about using stuff I wrote or co-wrote for the pidp8i project that scripts arbitrary actions under OS/8 to enable building arbitrary media. It made the pidp8i stuff 100% reproducible, but I wrote it with an eye to enabling people with physical hardware to create arbitrary media for themselves.

If you don't already have a pidp8i build environment and tool chain, you do have to learn a bit of a possibly unfamiliar version control system, fossil. To the inevitable question of "Why didn't you use git like everyone else?" I have the following response:

1. We do export to
2. fossil offers a whole github-like experience with a single tool download.
3. It was easy to use fossil for what we wanted.
4. Since we used fossil, all our docs are about collaborating via fossil instead of git.
5. Fossil is available on all platforms, including Windows.

To do this:

1. Follow the instructions at:
to install fossil, and clone the pidp8i repository.
2. Follow the instructions at:
to configure and build the tree, skipping over the initial stuff that assumes you're doing this on the pidp8i raspberry pi. Start with the section "Configuring, Building and Installing".
3. Look at existing media build scripts in the media/os8/scripts directory. The file explains what they all are. (I'll apologize in advance for the complexity of all-tu56.os8. I wanted a single script that would build bootable tu56 images with either OS/8 v3d, or from-source built OS/8 v3f for either TC08 or TD8E system drivers. I got it, but new readers may find there's a lot to take in.)
4. Read the os8-run manual at to learn how to write scripts of your own.

Why you want to do this:

How many times have you been running BUILD, made a mistake, and had to start all over again? Wouldn't you like to just script that?

Wouldn't you like to be able to make bootable media with your own custon updated version of languages like FOCAL or utilities, and share that media with the world?

The os8-run scripting environment lets you create blank media, copy in arbitrary files from other media, or the simh hosted filesystem, run arbitrary keyboard monitor scripts to perform assembly, linking, etc. and to run BUILD to modify driver setups, and even to build a new system head with KBM and CD binaries your script has built.

I'll be happy to answer questions people have about running this stuff. I REALLY want to see this development become useful not just to owners of the PiDP-8/i but also the bigger PDP-8 community.
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