ADAPTER CIRCUIT FOR TRACKBALL DEVICE

An adapter includes a program-controlled microprocessor provided with input means adapted to be coupled to the output of a trackball-type position control device, output terminals and selection means for selectively conditioning the processor for operation in either of two modes. In one mode the adapter converts the trackball output signals to a form which can be inputed to a port adapted for use with a switch-type joystick and yet includes both speed and direction information. In the other mode the adapter converts the trackball output signals to a form which can be inputed to a port adapted for use with a trackball device. A ladder network is connected to the adapter output terminals in its second mode for converting the output signals to a form which can be inputed to a port adapted for use with a proportional type joystick.