Abstract: A manual entry data input terminal is provided having a keyboard including a set of key switches including one-half of a standard keyboard. A selector circuit is interposed between the key switches and an encoder circuit for enabling input of data bits to the encoder circuit in accordance with a first indicia series correlated to the conventional indicia display of the one-half keyboard or a second indicia series correlated to a mirror image indicia display of the opposite one-half of a standard keyboard. A mode selector switch connected with the selector circuit is selectively operable to enable input of data bits alternatively for either the first or the second indicia series to enable operation of the terminal by one hand.