STORED PROGRAMME-CONTROLLED DATA EXCHANGE SYSTEMS STORED PROGRAMME-CONTROLLED DATA EXCHANGE SYSTEMS

摘要

A method and apparatus for converting characters in a program-controlled data exchange installation is described. The exchange installation includes at least one common storage unit storing data and programs and processing units inter-operating with the storage unit in a cyclic manner. At least one of the processing units is a program control unit, and at least one is a line termination unit. An additional character handling unit is provided for carrying out character translation. The latter apparatus includes a connecting device regulating the traffic with the common storage, a control section controlling the operations for the various tasks to be performed and a storage section. The latter storage section forms a channel storage, which is divided into separate channel storage areas, each containing a series of channel locations. At the start of a character handling operation initiated by the program control, the channel locations are selectively allocated for the duration of a character handling operation, by entering a corresponding line number of the access line determined by the line number. In order for the character handling unit to receive instructions and data in the channel storage and to transfer message and data from the channel storage it gains cyclic access to specified areas in the common storage which are provided for the reception of instructions, messages and data.