19. A handheld data input apparatus comprising: a pressure-sensitive tablet; a coordinate detector for receiving a signal output from said tablet and outputting coordinate data corresponding to a pressed position on a detection surface of said tablet; a character processing means for extracting predetermined character data from time-serial coordinate data output from said coordinate detector; a document memory for sequentially storing the character data extracted by said character processing means; selection means for selecting the character data stored in said document memory or coordinate data from said coordinate detector; an interface means for outputting the character data or the coordinate data selected by said selection means to a host apparatus connected to said handheld data input apparatus; and a casing integrally incorporating said tablet, said coordinate detector, said character processing means, said document memory, said selection means, and said interface means.
29. An apparatus according to claim 19, wherein said document memory is formed in an integrated circuit card.