Microprocessor and control apparatus in a photocopier

A control system for a reproduction machine comprising:

• a. a master programmable controller including an arithmetic and logic unit, and program storage means for storing an operational program for controlling said machine,
• b. plural intermediate controllers, each of said intermediate controllers controlling a discrete portion of said machine,
• said master controller controlling said machine solely through said intermediate controllers,
• c. said intermediate controllers including at least one passive controller and at least one active controller, said active controller having an arithmetic and logic unit and program storage means for storing a subprogram for controlling one of said discrete machine portions,
• d. means for sensing analog signals from said machine,
• e. analog-to-digital conversion means for generating digital signals from said analog signals,
• f. means for inputting said digital signals from said analog-to-digital conversion means to said active controller for processing by said active controller in accordance with said subprogram,
• g. digital-to-analog conversion means for converting signals processed by said active controller into analog signals,
• h. means for controlling said one machine portion in response to said analog signals from said active controller,
• i. means for imputting said digital signals from said digital-to-analog conversion means to said controlling means, and
• j. timing means for operating said master controller and said intermediate controllers in synchronism to control said machine.