Over the years there have been many joystick interfaces released for the Electron. The first was a small cartridge made by First Byte which fitted onto the rear edge connector. This needed a special program for each game with which it was to be used. It had no edge connector at its rear and so no other add-on could be fitted while this was in use.

Acorn's own Plus 1 interface allowed analogue joysticks to be used. The problem was that only a few games had analogue joystick options. Wizard Development produced a unit called the Sidewinder which, like the First Byte interface, fitted onto the rear edge connector. This interface did have another edge connector so that additional peripherals such as the Plus 1 could be fitted as well.

Each of these interfaces had some design or software fault which meant they were difficult to use. Slogger has come up with a practical switched joystick interface which has all the best features of its predecessors without the design faults. The package contains a ROM, the interface and a user guide. The ROM has to replace the one which sits inside the Plus 1 unit. Removing the old ROM and replacing it is a simple procedure that any one can do. The user guide explains clearly what to do and how to do it so there should be no problems.

With the new ROM inserted, the interface can be plugged into the front cartridge socket of the Plus 1. On the top edge of the cartridge is the D-type socket into which you plug any Atari-type switched joystick.

Actually using the interface with software is a little bit difficult to get to grips with at first. The user guide explains that the new ROM provides a * command that allows the joystick to emulate the pressing of five keys. An example is given to allow the very popular key combination: Z - Left, X - Right, : - Up, / - Down, SPACE - Fire/Action to be emulated by the joystick. The command is *JOYSTICK 3 -73 -105 -98 -67 -99.

The first number is a code which indicates the mapping address the interface is using. This can be altered by changing the positions of switches inside the interface cartridge. Because of this, the interface is fully compatible with any other peripheral which uses a mapping address. The negative numbers in the command line are the internal key values of the direction and fire keys. A list of all the keys and their values is given in the user guide. When the *JOYSTICK or *J. command has been given the software can then be loaded as normal.

When testing the joystick interface with various games I found that the majority worked well with only a few exceptions. The use of joystick with games such as Combat Lynx and Pengi made them much easier to play and hence more enjoyable. Installing the new Plus 1 Operating System ROM has some added bonuses. Cassette loading and saving bugs have been ironed out. Selection of language ROMs is now manual instead of automatic as with the old ROM. The user guide gives all the information needed to use the interface including how to use the interface with your home-written programs.

The whole package is designed to ensure that the hardware and software will cause no compatibility problems. This kind of attention over detail is something other Electron add-on companies would do well to copy. Getting used to the *JOYSTICK command is somewhat difficult but the results are usually pleasing. If you play lots of games and miss having a joystick option then this interface is a must.