One of the understated and wrong assumptions about the Raspberry Pi is that you can try any flavour of Linux on it but Linux is really the only OS.  It is true that most of the 20+ OS that you can try are based on Linux but there are a few that aren’t.

• Windows IOT Core – a limited version of Windows
• Risc OS – Created by the inventor of ARM
• RaspBSD – More Unix than Linux.
• Chromium OS. Turn your Pi into a Chromebook.

Of these, I think Risc OS looks the most interesting. It certainly isn’t Linux and it reminds me of the Archimedes, the first ARM computer.

Risc OS is 33 years old, it started in Cambridge in 1987 and is a descendant of the BBC Micro OS. And yes they do have a BBC BASIC available.  There’s  lot more background to it on this page  but bear in mind that it and the comments date back to 2012. It has an  ARM C compiler called Norcroft.

I won’t be oing any more with Risc OS, but thought it worth a mention. All of the stuff I’m doing will be on Linux OS.

Not. ARM is in the news because Apple have just announced that they will be transitioning from Intel CPUs to ARM over the next year or two.

ARM being the CPU brand inside Raspberry Pis. This is a collection of talks and links to articles about the ARM architecture, concurrency, performance and way too much other stuff to list. There’s a lot in there and I defy anyone with the vaguest interest not to find something of interest.

I’m not a hardware person myself, but dipping into stuff like this can yield benefits. Remember the CPU in the Pi 4B has four cores. If you are writing software that just runs one one thread then it’s like driving a car with a four cylinder engine but its only firing on one. And if you manage to write software to use all four cores, do you know how to avoid false sharing? (Yes it’s a thing!)