A data processing system input device

Claim 1

A data processing system input device including a keyboard and electronic circuitry associated to said keyboard, said keyboard permitting a fully blind and rhythmic access for actuating human fingers without an auxiliary keyboard for feeding data into a data proces­sing facility, said keyboard comprising - a left and a right array of keys each array including a plurality of data keys having the functions of character, numeral and symbol keys, a space key and a first shift key; said data keys, space key and first shift keys of both of said right and left arrays together, a "carriage return" key in at least one of said arrays of keys and a further first shift key in one of said arrays of keys essentially constituting and providing all functions of a given standard keyboard for typewriters; - a second shift key; said electronic circuitry comprising - a plurality of key switches each associated to one of said keys and including contact means actuable by the corresponding key for generating a key actuation signal when the corresponding key is actuated; - a plurality of coding unit means each comprising a plurality of coding units; each coding unit being responsive to a key actuation signal to generate a code signal representing a specific key function for the control of the data processing facility when actuated by a key actuation signal; - a first switching device responsive to all first shift keys and being operative for coupling the contact means of the data keys of both arrays of keys alternatively to a first or a second coding unit means both of which together being capable of generating code signals for the complete alphanumeric character set and auxiliary functions of said standard keyboard for typewriters; - a second switching device controlled by said second shift key for coupling at least some of the contact means of said data keys at least to a third coding unit means which includes code units being capable of generating code signals for controlling functions of the data processing facility including those for a cursor control; - said first switching device comprising a bistable circuit actuable by a signal of key actuation from said further first shift key for alternatively producing first and second output signals for selecting alternatively said first or second coding unit means to enable the selected coding unit means to be responsive to key actuation signals, and further comprising gate means for producing said first signal only when no shift key is actuated, and providing said second signal when one of said shift keys is actuated; - said second switching device comprising a second bistable device having an input coupled to the key switch of said second shift key for receiving a signal which changes the state of said bistable device, each time when said second shift key is actuated; said second switching device further comprising gate means coupled to an output of said second bistable device and receiving said output signals from said first switching device, said gate means being arranged to pass said first and second signals from said first switching device to said first and second coding unit means, respectively when said second bistable device is in a first state, and passing at least said first signal to said third coding unit means to enable said coding unit means to respond to key actuation signals when said bistable device is in a second state of operation.