Method and system for simultaneous operation of multiple handheld control devices in a data processing system

The receiver for simultaneously receiving control signals of at least a first and a second frequency from a plurality of remote control devices, comprising;

• a transducer for simultaneously receiving first and second carrier signals and converting the signals into a composite electrical signal;
• a splitter for separating the composite electrical signal into first and second component signals having the first and a second frequencies;
• and
• first and second demodulators for deriving the control signals from the first and second component signals.

A display control system for simultaneously receiving control signals from a plurality of remote input control devices comprising:

• a first remote control device having a control element movable in an X-Y plane, for producing first control signals in response to manual input, and a transmitter which transmits a first carrier signal having a first frequency modulated by the first control signals;
• a second remote control device having a control element movable in an X-Y plane, for producing second control signals in response to manual input, and a transmitter which transmits a second carrier signal having a second frequency modulated by the second control signals;
• a receiver having a transducer for simultaneously receiving the first and second carrier signals and converting the signals into a composite electrical signal;
• a first filter connected to receive the composite electrical signal and provide a first component signal, the first filter allowing signals having the first frequency to pass while blocking the signals of the second frequency;
• a second filter connected to receive the composite electrical signal and provide a second component signal, the second filter allowing signals having the second frequency to pass while blocking the signals of the first frequency;
• and
• first and second demodulators for deriving the first and second control signals from the first and second component signals, the first and second control signals controlling first and second display elements on a display device.