As you are no doubt aware, the unexpanded Electron can't use joysticks - it has to have a joystick interface added to it.

So if you want to play games with a joystick, you have to pick up a joystick interface. And, to pick wisely, you have to know exactly what you're after.

This is because joysticks work in two ways. There are analogue joysticks - they are the kind that the Plus 1 supports. And there are switched, or "Atari-style" joystick - the kind that every other interface supports. Whichever interface you choose will use one of these methods.

This leads to the problem that games written for one type of joystick won't work with the other type. So you may end up with an analogue joystick that won't operate games written with the switched joystick in mind and vice versa.

Until now the remedy has been to use software patches - programs that are loaded before the game which attempt to bridge the gap between the two types of joystick operation: Joyplus in the April issue of Electron User is an example of this.

The trouble is that no matter how good the software patch is, some games still won't work. Also, if you're like me, you'll often load the game, then remember that you should have loaded the patch first.

One answer to this problem has come with Power Software's Electron Joystick Interface.

This is a small, neat interface box that fits snugly onto the back of the Electron. It takes the standard 9-pin D-type connector switched joystick and allows the Electron to play switched joystick games.

However, it does much more than that. Inside is a ROM chip that contains a software patch allowing the Power interface to work with games written for analogue joysticks. These are primarily Acornsoft games.

This software is available instantly at the call of a *JOY command, which is far quicker than loading cassette-based patches.

It's easy to fit and simple to use. The instruction sheet, which comes on the back of the twelve months warranty card, is thorough and easy to understand.

Once fitted, the *JOY command invokes the ROM software. This then takes you through a menu of choices which allow you to specify which joystick movements are to take the place of which keys. Then, when you are sure everything is right, you load your program as normal.

It's an excellent piece of hardware that I thoroughly recommend. While I can't guarantee that it works on all games - I haven't got them all! - it has certainly worked on all the ones I've tried.

This alone would be enough to recommend it. But the ROM-based software along with the simple but thorough instructions make it a winner.