Today I received a large haul of Acorn related machines and parts. With it comes a story and a quite rare machine.

The Story

In the background, I’m slowly working on my RiscPCs and other Acorn gear. Amongst other things, I’m planning on upgrading my main RiscPC to a two-slice system (basically double-height, more expansion bays). I purchased a 4-way backplane for a RiscPC so that it could be extended to have cards all the way up.

With it came a letter, the person who sold it recognised the town I live in, he used to be based at the local RAF base (which was decommissioned many years ago). He is an Acorn computers enthusiast and had more things to sell as he was moving house soon.

We got chatting and I agreed to drive the 1.5 hours to his house to purchase more of his Acorn items. His Acorn background goes far enough that he knows Sophie Wilson!

The Haul

When I got home, I took a photo of everything I had bought.

In this haul there is:

• Most of a two-slice RiscPC 600 with a StrongARM upgrade (top cover, some pegs and PSU missing). Including keyboard and mouse.
• Two SCSI podules
• Two Midi podules
• Two SCSI scanners
• A whole pile of Acorn Archimedes and BBC Micro books
• 8 SCSI hard drives
• A SCSI CDROM drive
• An IDE CDROM drive
• A SATA DVD drive
• A bunch of new PS/2 mice
• Some more miscellaneous stuff
• The Big Brown Box! (the rare machine is in there)

It took me a while to unload all of this, and it is going to take me longer to sort through it all properly. But I want to focus on the box for now.

Big Brown Box

This is something special. A machine so well loved that I believe this case may have been custom made for it.

It is double-sided, as in the top panel and the bottom panel both come off, there is also a handle on one side to carry it, although I think it is fragile enough now that I won’t use the handle.

With that being said, let’s take off the first lid and see what is inside…

It is an Acorn Atom! For those who don’t know, the Atom was the predecessor to the BBC Micro computer, they are pretty hard to come by nowadays, and it is unknown if this one even works. From this image, you can see some similarities in keyboard and case design. It was released in 1979, which is even before the Sinclair ZX80. It used a 1MHz 6502 CPU coupled with 2KB of RAM (upgradable to 12KB).

Now let’s flip the box over and see what is in the other side.

A partition to neatly hold cassette tapes of Atom software, the PSU, some extra ROMs and a bunch of manuals and paperwork.

I took photos of everything inside after I unpacked it.

For some reason, the PSU’s connector has been cut off. I do wonder if this is because the PSU is bad, or whether the machine had been converted to 5v. I say this because the PSU is 8v and feeds directly into two 5v linear regulators inside the Atom (which can get quite hot). A rather common modification made to the Atom was to add a link wire to bypass the regulators and just give it 5v input via the PSU connector.

Unfortunately, there is no tape drive with the machine, so I’m going to need to purchase one of these and find a way to get a good video out, as it just has a TV modulator inside of it.

The Atom Itself

Now let’s take a look at the machine.

It is going to need a good clean, the screws in the bottom are missing, as is one of the feet. But the feet are the same 3M type that Amigas use, so I have lots of those spare.

If we flip it over and take off the bottom, we can see the main PCB inside.

At the moment, I don’t know enough about the inside of Atoms to know what I have here. This will be a machine I’m learning from as I’m restoring.

Coming Soon

I’ll definitely be blogging about the restoration process of this Atom, and how it works, as I learn more. I’ll then likely focus on the RiscPC and all the accessories that came with it. I also need to find some room to put it all, it is currently all on my PCB cleaning bench whilst I find space!