Apparatus for coding input data characters from a keyboard incorporates apparatus for recognizing characters which are to be represented by two successive code representations, rather than the usual single code representation for each character. When a two-code character is recognized, ordinary operation of the apparatus is inhibited, and an auxiliary counter is energized which, in conjunction with a fixed-value storage device, causes the plural code signals to be generated in the correct sequence, after which normal operation of the apparatus is resumed.

A method and apparatus are disclosed for addressing a character generator memory containing symbols common to two or more languages in a common area of the character generator memory. Symbols which are special to the particular language being displayed are stored in one of a plurality of special symbol areas of the character generator memory. One of the special symbol areas contiguous with the common area is identified as a default symbol area. The proper special symbol area of the character generator memory is selected by comparing the high order bits of a display character code with compare bits to determine whether a different special symbol area of the character generator memory is to be substituted for the default area contiguous with the common area. If the compare bits indicate that a different special area of the character generator is to be substituted, the high order bits of the display character code are not directly used to address the character generator memory but are replaced by substitution bits to access that special symbol area unique to the language being displayed.

Keyboard apparatus is described in which a keyboard having dead-keys to enable accented characters to be entered is claimed. A storage means, preferably of read only type, is divided into a number of sections; each section contains character codes representing accented or non-accented characters associated with that section. When a given dead key is activated, this addresses a section of the store associated with that dead-key to access the section containing the characters which are accented with the accents associated with that dead key. Activation of the next character key causes accessing of the code for an accented character within that section. Different accents for the same or other characters can be associated with different dead keys. Optionally the store can be arranged to store only validly-accented characters, thus avoiding the entry of invalidly-accented characters. Non-accented characters are normally accessed from a single section of the store. Common accented characters do not require dead-key operation.

A liquid crystal display character generator circuit comprises a first RAM for temporarily storing information to be displayed on a liquid crystal display unit, a ROM for storing standard character patterns corresponding to the information to be displayed, a second RAM operable to store special character patterns corresponding to the information to be displayed, and a data selector for enabling the designation of an address in one of the ROM and the second RAM in accordance with the information stored in the first RAM.

A character code generating device includes a standard character code correspondence table for storing the character codes each corresponding to individual key-inputs from a key board, a searching device for the for said standard character code correspondence table to generate the character codes corresponding to the key-inputs, a supplementary character code correspondence table and a judging device. The supplementary character code correspondence table serves to store the character codes different from those in the standard character code correspondence table with respect to the specified key-inputs from the key board. The judging device determines whether the search of the supplementary character code correspondence table is required or not. Upon a determination relative to the search of the supplementary character code correspondence table by the judging devices, the searching devices operates to preferentially search the supplementary character code correspondence table prior to the standard character code correspondence table.