No bigger than one of those upright Kempston printer interfaces, the Robotek from Datel is a neat gizmo which controls robots and sensors.
It contains four outputs, to drive external devices, and eight inputs which gauge the status of sensor equipment. The output channels are controlled by on board relays using Sinclair Basic Out commands. Each relay has three control lines which are connected to your external device using a ribbon connector. The ribbon connection chart included with the package shows the lines through which you'll have to send instructions to activate your robot's motors. Unfortunately, since the cable is only 66cm long your robot won't get lost.
Robotek is mapped to Port 63, so if you type Out 63 followed by a number greater than zero the corresponding relay will be switched on. That relay will continue to operate until you issue a Close command using zero.
The interface also contains eight input channels, labelled A to H, which are connected to sensing switches in your robots, turtles, arms or buggies. Some simple software, not included with the device, will sense which of the lines in the device has been activated. For instance, if you place a sensor line at the front of your turtle that line would be activated if it bumped into a wall.
Robotek is simple to use but its two pages of A4 instructions leave much to be desired. Datel should provide more support for such an excellent device and back-up for existing customers. Datel does, however, recommend a book which you can buy to build Lego robots and operate them using the company's interface. It's called Make and Program Your Own Robots and can be obtained from Arrow books for £3.1
A good robot controller and sensing interface, but the instructions could be a good deal more enlightening.