Abstract: A combined home-use-television set/calculator electronic system comprising a control unit for conducting arithmetic calculations and for displaying calculation results on an image screen of the home-use-television set. A keyboard unit is exchangeably connected to the control unit for increasing operation abilities of the combined home-use-television set/calculator electronic system. A read only memory cartridge is exchangeably secured to the control unit. A read only memory corresponding to a selected keyboard unit is secured to the control unit for developing operation instruction signals which are required for performing the arithmetic calculations associated with the selected keyboard unit.

Abstract: A combination of an electronic calculator, a home use television receiver and a signal converter interface is suited for displaying a coordinative representation calculated from the calculator onto the image screen of the calculator or onto the image screen of the television receiver. There is included the signal converter interface for converting outputs from the calculator into signals of the form competent with the television receiver (that is, a composite television signal).