HoM: Computers: Electron

ADFS::Web.$.computers.Electron.index/html

Acorn Electron

The Acorn Electron
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This is an Acorn Electron, the first computer I ever owned. Less powerful than the BBC A and B series, it was a cut-down consumer friendly machine for people like me who couldn't afford the mighty Beeb.

Notice the "data recorder", in this case a bog standard Boots brand tape recorder. Although the Electron eventually had several add-on floppy disc interfaces made for it, being the cheap and cheerful, less powerful machine meant that even if you could afford them it often wasn't worth it. The number of times I played Elite and had to start from scratch having taped over the data file on some random C90 ninety-minute tape doesn't bear thinking about though.

My real Electron #1 went back after just a couple of weeks with a broken keyboard; this is actually a replacement one which one served me for ages until I again broke the keyboard, this time by hard-wiring part of an old calculator keypad into it as an Elite weapons console (sadly not covered by the warranty). A full replacement keyboard would have cost as much as a replacement machine, so I saved up and bought a Slogger 64K Turbo Electron instead - a proper Acorn Electron but with extra hardware that gave added functionality at the flick of a toggle switch (and a hard reset). A little later I got a reconditioned second-hand keyboard for fifteen quid which means both machines are now back to full working order.

An Acorn Electron loaded with goodies.
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This is my other Electron, the upgraded one. The first box bolted onto the back is a Slogger ROM Box, which allowed the Elk to use BBC-style ROM chips to add word processoring capabilities (such as AcornSoft's View, one of the chips in the picture), new commands (such as printing control, file systems etc.) or new programming languges (such as Forth, which I think is the leftmost ROM as you look at the image). Behind this is an official Acorn Plus 1 expansion, which added the missing printer and analogue (joystick) ports, plus two cartridge slots. These slots could take carts which could do pretty much the same as the ROM chips on the ROM box, plus could take other hardware interfaces (such as a third-party floppy disc interface), and also game carts - mine came with Starship Command. In this picture you can see a large cartridge with a red stripe, which is an Electron second processor - I didn't even know these existed, I picked this one up many years later - and a toggle switch on the right hand side of the picture shows this is a Slogger hacked version with Turbo and 64KB/Turbo modes.

What the hell did you use it for?

Memory was always tight on the Electron - it had 32KB of memory, up to 20KB of which could be eaten by the screen memory requirements (it didn't have a MODE7 teletext mode like the BBC, which only took 1KB of memory for a whole screen full of text and psuedo-graphics). Add the Plus One upgrade, and then a Plus 3 if you could afford it, to steal a little more space to operate in, and memory was almost none-existant. I think I could get about 1,000 words into the word processor before I had to spend about 10 minutes saving the result to tape, then loading the tape version back into an illegal memory area to make sure the tape itself was physically okay without overwriting the memory holding the document just in case I had to go through it all again. The Slogger version (pictured above) gave 32KB of real memory, as screen memory was taken out of the 32KB of sideways RAM this hack introduced, with anything left over potentially being used as a print buffer - but Elite wasn't compatible with this hack, so I left the machine in standard 32KB mode for a lot of the time.

I did however have great fun learning to program them using the built-in BASIC, including a multi-mode graphics package and a font editor for the 8x8 system font - both of which came in handy when editing the school magazine. When the Archimedes came out while I was at college I programmed them by writing the program on my Electron at night, saving to tape, using a Sony Walkman to transfer the data off the tape onto a BBC with a 5.25" floppy disc, and then on to the Archimedes using a serial transfer lead. A couple of small files could take all morning to set up and transfer.

Another fun thing to do was find a radio/cassette machine with the motor control input used by the Electron to stop and start the tape; write a small timer program; and then when a favourite late-night radio comedy show started the Elk would start the tape and it was like a VCR for radio. You'd have to use some tin foil as a shield as the Elk really put out some radio waves, you could pretty much tell what part of a program it was running by listening to the interference generated on an FM radio.

I also heard that a fox had started using our suburban garden as a short cut home: I'd never seen a fox so I wired up a light sensor to the analogue joystick port with several metres of wire so that it could stretch from my window down in to the garden; put my Dad's bicycle light across from it (as I'd heard foxes couldn't see red light); and wrote some software that automatically adjusted for slight changes in light level over the course of the night, thresholding to account for slight deviations, and a two-tone alarm that once triggered would keep going until I pressed the reset switch (AKA space bar). It was also pre-programmed to switch itself off just before (false) dawn, and had an on-screen graph display of the past hour or so's light readings. With so much prep work for one night of use you're probably expecting me to say that it didn't work, but about 3a.m. the alarm triggered, I flew to the window and there was a fox: it stood right in the middle of the lawn for several seconds looking around behind it, probably wondering what the hell the alarm was, before trotting off to a hole in the fence.

Oh, and I played Elite on these machines. A lot.