With much thanks to some others in this group (brave souls?), the install has been tweaked and some compiler version issues fixed. If you want to try it:
This has been tested by me under Ubuntu
24.04.5 and a Pi5 running the latest Debian
Bookworm, both as clean installs and parallel installs. I have not built on a pi4, but there is a report that the version of gcc on at least one version of it is an older one and has issues compiling. I'll dig out a pi4 and check that out.
Finally, if you do a parallel install with the original pidp1, be SURE you are running the binaries you think you are. This means the desktop program icons in particular! Mixing old and new programs is quite likely to produce strange problems. If you tell the mod version to install into the OS, it will make sure the old links, if any, are updated. It will also update the desktop apps if asked.
To beat this to death a bit more, if you do a parallel install, I strongly suggest you run the various commands directly from the /opt/pidp*/bin directories. I think one reported issue was because of mixed versions.
Bill