Patent US 4,079,449

A visual display for an electronic accounting computer comprising a keyboard and a console. The computer concurrently executes two programs. The console is provided with a changeover switch for selectively allocating the keyboard, the display and the console to one of the programs. As introduction from the keyboard is required, an operator guidance message is displayed. This message is replaced by the response of the operator when it is initiated. If the program not selected by the allocating switch requires attention, an operator call message is developed. The changeover switch is moved to select the program requiring attention. An appropriate message requesting the needed data is displayed, to be replaced by the data as the operator introduces it. The operator then repositions the allocating switch, and the message defining the next required introduction of the original program is displayed, so that data introduction may resume.