A device for the use of and easily portable by an individual, consisting of a main memory, a microprocessor, a keyboard for the control of the microprocessor, etc., and at least one accounting memory and a display. Operation of the keyboard in a pre-determined fashion will cause the microprocessor to...http://www.google.de/patents/US4460965?utm_source=gb-gplus-sharePatent US4460965 - Device for the use of and easily carried by an individual
