Stage lighting control unit

Claim 1

An improved stage lighting control unit of the kind comprising in combination: a. a memory store having ''''write'''' and ''''read'''' lines and defining a plurality of lighting effect memory elements and two continuously modifiable ''''active'''' memory elements, said two ''''active'''' memory elements being alternatively connectable to said lighting effect memory elements, b. a dimmer control signal generator having an output which is connectable to the ''''write'''' line corresponding to either of said ''''active'''' memory elements, said generator, when said output is so connected, operating continuously to modify the contents of the ''''active'''' memory element thereby defining a sequence of dimmer control signals in said corresponding ''''active'''' memory element for storage in a corresponding lighting effect memory element from said plurality thereof, c. a master fader unit having an output that receives the concurrent value of a sequence of dimmer control signals from the ''''read'''' line of one of said ''''active'''' memory elements, and an input connected to the ''''read'''' line of the ''''active'''' memory element to which said output of said dimmer control signal generator is connected at any time, d. a plurality of dimmers having corresponding inputs connected to said output of said master fader whereby each of said dimmers is controlled in dependence upon the concurrent value of the corresponding dimmer control signal in the sequence in said corresponding ''''active'''' memory element subject to continuously variable control by the dimmer control signal generator, and e. display means associated with each of said dimmers and having an input connected to a second output of said master fader thereby to indicate the application of control signals to each of said dimmers, wherein the improvement comprises the provision in the ''''active'''' memory element, in addition to said two continuously modifiable memory elements, of a backing store having lines connected in information-transmitting relationship to and from said lighting effect memory elements, and a further set of lines connected to said continuously modifiable ''''active'''' memory elements whereby information passes solely from said backing store into said continuously modifiable ''''active'''' memory elements.