When I was much younger, I had a BBC Micro computer at home. A few friends had Acorn Electrons, and I saw them at the time as the inferior sibling to the BBC Micro.

Roll on to today, and I have a BBC Micro or two, which was originally called the Acorn Proton. I also have the Acorn Atom. So, it was inevitable that I would end up acquiring an Acorn Electron too. But like buses, two turned up at once!

The Electron

The Acorn Electron is basically a smaller, cost reduced version of the BBC Micro aimed at home computer users. A majority of the logic got moved into a single ULA logic chip, which was an incredible feat of engineering at the time. But several other cost reduction measures were made.

There is no mode 7 out of the box in an Electron, and the memory bandwidth is essentially halved. So, whilst being somewhat compatible, a majority of games had to be ported over. They often lost horizontal scrolling between screens in the process. In addition, many of the expansion ports are missing, but they can be added using modules on the back of the machine.

This is the pile of Electron gear that recently turned up.

Here I have:

• A complete Acorn Electron in the original polys, this one I know is working.
• Another Electron, which is known to be faulty.
• An Acorn Plus 1 expansion. This adds a couple of extra ports and a couple of cartridge slots.
• A P.R.E.S. Advanced Plus 3, which is a disk interface for the Electron.
• Five games on tape, boxed.
• The Introductory Cassette that comes with an Electron as standard, much like the “Welcome” tape with BBC Micro computers.

Here is the fully working one assembled, with one of my GoFloppy drives, running a game.

To make this work, I did modify the P.R.E.S. cartridge to make it use DFS as well as the stock ADFS. This allows support for more disk types. A RAM upgrade is also possible in the spare socket, and I will be doing this.

But, as this is my blog, so you aren’t reading this for the working things, you want to see the broken things. Let’s wheel out contestant #2.

The Faulty Electron

Let’s pop the lid off, and see what is underneath.

You can see how simple the board is. The brown PCB is the PSU board, it takes a 19V AC in (it can run on less) and gives out a +/- 5v DC output to the motherboard. This is an issue 4 board. What I do know about these is that the ULA socket (the square metal thing in the middle) can be a bit funky. When powering up the machine, we just get a black screen, so that is likely the issue. But first, let’s test the PSU.

It is a little low, but looking at the service manual found online, this is within tolerable range. So, we do need to look at the ULA.

I popped off the retention clip and removed the chip. Whilst it is difficult to see, several of the spring contacts have snapped and are wedged down.

Whilst these sockets do not appear to be manufactured any more, they are still obtainable. Intel also produced CPUs in this CLCC-68 format.

With a quick run with the Hakko FR-410 desoldering gun, the socket was easily removed, and I replaced it with a new one.

The chip was then popped in and locked into place (this is a really tight lock, it required a scary amount of downward force before you can pull the locking arm over it.

Note that this machine does require the keyboard connected to boot properly. So, I reconnected this and tested.

Success! It was as simple as that.

With a little bit of a clean-up the body was also looking a lot nicer.

Conclusion

I am more impressed than I thought I would be by this cute little machine. I even hooked up my ANF03 tape machine and loaded a couple of the tape games that came with it. My intention is to keep one of the Electrons for my collection and sell the other one on for someone else to love and relive their Acorn memories with.