Data processing system

摘要

A data processing system has a computer 50, a keyboard 48 which is connected to the computer 50 via a keyboard line 46, 47, and a control device 49, which is arranged in the keyboard line 46, 47 and comprises a dedicated power supply 24, a microprocessor 6 to 10, 11 to 20 and at least one circuit-breaker 26. The circuit-breaker 26 is provided for making and breaking an external power supply line, in particular that of the computer 50. The control device 49 switches the circuit-breaker 26 as a function of signals from the keyboard 48 and/or from the computer 50 which are transmitted via the keyboard line 46, 47. The microprocessor of the control device 49 is connected in series with the keyboard 48 and the computer 50 via the keyboard line 46, 47. The microprocessor evaluates the signals from the keyboard 48 and the signals from the computer 50. As a function thereof, it makes and breaks the keyboard line 46, 47 between the keyboard 48 and the computer 50 and switches the circuit-breaker 26. The microprocessor generates additional signals as a function of the signals from the keyboard and/or from the computer and transmits the said additional signals to the keyboard 48 and/or to the computer 50 via the keyboard line 46, 47.