The Electron has acquired an unfortunate reputation as being a slow micro, but this actually isn't so. For instance, it's much faster than its competitor, the Sinclair Spectrum.

This misconception has arisen through living in the shadow of its big brother, the BBC Micro. Any home computer compared with this will seem slower.

This won't placate Electron users though - they want their machine to be every bit as good as the BBC Micro. Now Slogger has come to the rescue and you can give your Electron a big boost in speed with an Elk Turbo-Driver.

The Turbo-Driver is a small board which fits inside the Electron. Apart from a switch on the side of the case, there's no indication that it's there. Flick the switch up and you're in turbo mode, flick it down and you're back to normal.

The board plugs into the 6502 processor and Basic sockets on the main circuit board. It's quite easy to fit to very early Electrons since both chips are simply plugged into their sockets.

Most Electrons however have the chips soldered in and getting them out isn't too easy. Send your machine to Slogger and they will fit the board and return it within seven days - quite an impressive service.

So how good is the Turbo-Driver? In Table 1 you'll see the results of five speed tests when run on a standard Electron, Turbo Electron and BBC Micro.

Test 1 is a simple maths program calculating SIN, COS and TAN. The BBC Micro comes out on top as you'd expect, but the Turbo is a very close second with the standard Electron taking as half as long again, so there's a significant increase in speed.

Test 2 is the same as Test 1, the only difference being that Test 1 was run in Mode 5 and Test 2 in Mode 1.

The results clearly show a drastic reduction in the performance of the standard Electron. It ran almost three times slower than the BBC Micro and Turbo, which were unaffected by the mode change.

Tests 3 and 4 are again identical, except that Test 3 runs in Mode 6 and Test 4 in Mode 1. An array is dimensioned and filled with a value. Notice that the BBC Micro is again quickest, with the Turbo close behind, and that there's little difference between Mode 6 and 1. The standard Electron is only slighter slower in Mode 6, but again it's three times slower in Mode 1.

Test 5 is a graphics program running in Mode 2. The BBC Micro easily wins with the Turbo not far behind. The standard Electron is three times slower, as before.

These simple tests clearly show that a BBC Micro is still slightly faster than a Turbo Electron, although you probably won't notice the difference.

The speed increase over a standard Electron varies depending on what it is doing and in which mode it is running. You'll see the biggest differences in Modes 0 to 3.

Benchmarks are all well and good, but they don't tell the whole story. What is the Turbo like in normal use? A common question we asked is: "If I buy the Slogger Turbo, will I be able to run all BBC software as long as it doesn't use Mode 7?" The answer to this is definitely no.

All the Turbo does is speed up the Electron - nothing more, nothing less. If a game doesn't run on a standard Electron it won't run on a Turbo Electron either.

If a BBC game crashes after running for one minute on a standard Electron it will crash after twenty seconds on a Turbo Electron because it's running three times faster.

However, much Electron software is improved and given new life by the boost in speed supplied by the Turbo. It puts extra zip into the cars in Frogger, the aliens are meaner in Space Invaders and the ghosts in Snapper seem jet propelled.

Some games are simply too fast now. Alligata's Blagger and Tynesoft's Mouse Trap are unplayable. This is why there's a switch on the side of the Electron to set it back to normal speed.

Aardvark's Frak and one or two other games still run at the same speed and the Turbo makes no difference at all.

Some BBC software does work on the standard Electron, but the games run so slowly that they aren't much fun at all. For instance, Ghouls Of Azzod, Morris Minor and USS Endeavour are three superb games from recent issues of The Micro User that all run on the Electron.

However they're so slow I can't imagine anyone wanting to play them. All these games run at their normal speed on a Turbo Electron and are great fun to play.

So it's fair to say that the Turbo instantly increases the amount of software available for the Electron, though it doesn't turn your Electron into a BBC Micro.

To sum up, the Turbo-Driver increases the speed of the Electron by up to 300 per cent depending on what it is doing. Much Electron software benefits by the increase in speed and the Turbo can be switched off for the rest. BBC Micro software which runs but is unplayable because of its slow speed now runs at the proper speed.

Having now used a Turbo Electron I can't bear the thought of going back to my old slow version. This upgrade should have been standard on all Electrons. I'd like to know why Acorn didn't think of this when it was designing the original.

Roland Waddilove