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Bailey, Christopher R. M.; Mandile, John R.; Peters, Daniel G.; Stonier, James W.; |
Network terminal driver communications subsystem

In a data processing system having a plurality of remote terminals, possibly of several kinds, connected by a plurality of communications media, also possibly of several kinds, from which terminals users may run a plurality of application programs in the central processing unit (CPU) of the data processing system, the CPU is provided with a network terminal driver for regulating transmissions between the various application programs and the various types of terminals over the various types of communications media. Means are provided for specifying the characteristics of the various types of application programs, terminals, and communications media, and the network terminal drive is responsive to those means.


What is claimed is:
1. In a data processing system comprising:
a central processing unit (CPU);
a memory unit connected to the CPU for storing system programs and application programs to be run by the CPU and for storing data to be operated upon by the programs;
a plurality of terminals of one or more types at which users enter commands requesting application programs to be run by the CPU and view results of those programs; and
one or more communications media of one or more types, each for interconnecting the CPU with certain of the terminals of the plurality of terminals,
a network terminal driver operatively connected between the CPU and the communications media for facilitating communication between the application programs and the plurality of terminals, the network terminal driver comprising;
a plurality of application modules, each associated with a different data format used by the application programs, for specifying data formats being used by each of the application programs;
a plurality of provider modules, each associated with a different one of the types of communications media, for specifying the characteristics of each of the communications media;
a plurality of device profiles, each associated with a different one of the types of terminals, for specifying the characteristics of each of the terminals; and
means responsive to said specifications of data formats, communications media characteristics, and terminal characteristics for interpreting transmissions from the communications media and assembling messages to the communications media according to said specifications of data formats, communications media characteristics, and terminal characteristics.
2. The data processing system recited in claim 1, wherein further:
a certain application program encountering an instruction directing it to communicate with a certain terminal generates and forwards to the network terminal driver a first request block;
the network terminal driver, responsive to the first request block and one certain of the application modules according to the data type used by the certain application program, generates a second request block;
the network terminal driver, responsive to the second request block and to one certain of the provider modules according to the certain communications medium by which the certain terminal is connected, generates at least one third request block;
the network terminal driver, responsive to the second request block and one certain of the device profiles according to the type of the certain terminal, generates one or more fourth request blocks; and
the third and fourth request blocks are input to a lower layer service provider which is responsive to the third and fourth control blocks to perform communication over the certain communication medium to the certain terminal,
whereby the lower layer service provider performs the communication between the CPU and the certain terminal according to the data type used by the certain program, the protocol employed by the certain communications medium, and the characteristics of the certain terminal.
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