The Raspberry pi + RISC OS as a descendant of BBC computer, and getting emotional about RISC OS & Acorn computers

Compared to most of the people on this forum (or in the acorn computer community) I’m pretty young, about 29 years old.
My family used acorn computers until around the mid-late 90s, when the PC had become much more popular.
The first computer we had was the BBC Micro. Then around 1993 or so we got the A3010.
Sadly I didn’t learn to program at the time. I only really used the computers to play games – mostly from Micro User magazine disks on the BBC, and public domain stuff from the APDL on the A3010. I did occasionally poke around at the program listing of the games (which were mostly written in BASIC) changing numbers or deleting whole lines, just to see what would happen. Usually it just broke the games but sometimes interesting things happened.

The past couple of years I’ve been rediscovering Acorn computers – I got our old BBC micro out of the attic, I’ve been learning BASIC and writing programs for the BBC micro and RISC OS, reading PDF versions of the BBC user guides, and so on. Having got to know the BBC micro a bit better, I’m surprised to see how much (in terms of design and features) RISC OS inherited from the BBC’s MOS. For example, in modern RISC OS’s BASIC you can do stuff like “A%=65:CALL&FFEE” and it works just the same as it did on the BBC micro.

Having discovered all this, it now seems to me that a raspberry pi with RISC OS is almost like a direct descendant of the BBC Micro – I hadn’t thought of it that way before. It feels like being reunited with a long lost family member or something. Does anyone feel the same way?

Does anyone feel the same way?

I’ve said for a long time (read: always) that RISC OS is an ARM version of the BBC MOS with bells on. Indeed you could easily envisage modules as a sort of spiritual successor to sideways ROMs, never mind OSBYTE, OSWORD, and such.

In a way it was good, because the MOS was very well designed and amazing what they fit into it (when you compare with other 6502 based computers that were varying degrees of suck – Tube, for god’s sake, who thinks to put something like that in a home micro!?!).

But unfortunately the legacy is showing its own problems. There’s no unified API to read the keyboard state, for example, just random OS_Byte calls, just like the ones to read/write CMOS RAM bytes, or to control the colour blinking. Worse, there’s no API for dealing with, say, the text cursor other than pushing VDU bytes around – indeed this is showing up with people with silly large screen modes, you can’t set the text cursor beyond the 255th column as it’s a byte and that’s how far it counts.

However, it is certainly right to think of the Pi running RISC OS as a descendant of the BBC Micro. From the operating system itself to the ARM processor it’s running on, it pretty much all was born from the runaway success of the Beeb way back when.