Well, I still own the ancestor - a BBC B.

As a schoolboy I was one of a handful who were in the computer club. We had a CBM (PET) 3016, a few Acorn System Ones and a UK101 that was built by our physics teacher.

One day this big grey prototyping keyboard case turned up. There was a microcassette unit fitted for loading and saving programs, and the whole thing was connected to a colour TV via an umbilical cord that looked like a vacuum cleaner hose.

We were given task sheets with projects to complete on this unit, and we could control the TV from the keyboard, read Teletext pages AND download programs.

It was a fun piece of kit that stayed with us for a couple of months.

In hindsight, I realised that the unit was a pre-production BBC Micro and we'd been part of a pre-launch test programme thanks to that same physics teacher.

Wow! I have heard about these but have never seen one. And I was pretty close to the fire at the time so amazing that you actually worked with one. I did get a pre-production Archimedes when it was still in development and had a great time porting stuff to it.

My school got our hands on a couple of desktops that would dual-boot Risc OS and a Unix by a similar route. Think they were ex-demo machines.

(Looking at Wikipedia, I think they might have been R260s running RISC iX on the other partition).

Was this the one:

https://chrisacorns.computinghistory.org.uk/Computers/A500.h...

At Netherhall?