Changes

The circuit consists of two quad TTL OR gates (7417) which drive a simple discrete H-Bridge configuration allowing bi-directional control of each wheel seperately separately by setting the associated bits high or low. Two sensors mounted at the front of the base board allowed the robot to report making contact with an object. The motor hardware is controlled directly from the CPCs [[Printer Port]], which limited the movements of the robot to the length of the connection cable. The inputs are read through the CPCs [[Digital Joysticks|Joystick Port]]. A 2 Metre Meter ribbon cable was supplied for this purpose. The circuitry is non-intelligent, so all control is done through software on the CPC.