International Business Machines Corporation

William F Nemecek

Harry Cheselka

Dean A Stockwell

George C Macauley

Robert W Roefer

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.

Addressing system for a multiple language character generator

Disclosed is a display system having one or more display terminals, each of which includes a base unit which acts as a display and supports a keyboard for operation as a keyboard/display terminal, the terminal in turn interfacing with a plurality of features connected thereto. The features can be quite independent of the display, such as a card reader, or can be an operationally integral part thereof, such as extended capacity buffer operating jointly with the main buffer of the display, or can be interactive with the display, such as a selector pen or program function keyboard. The base unit and the features receive transmissions from a controller via a feature bus-out in the base unit and transmit to the controller via a feature bus-in in the base unit. The base unit also provides priority control in permitting features to respond to a controller poll. Commands are also directly addressable to the base unit and features by the controller, with the base unit performing interface functions between the controller and the features such as parity checking and time out error reporting.

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Kingston, NY, United States of America

William F Nemecek