Method and system for enhancing the efficiency of data communication between a terminal device and a host computer having an optimizer

In a data processing system having a host computer running an application that communicates with a terminal device through an optimizer, a terminal data stream is created in response to an operator input sequence at the terminal device. Thereafter, a selected combination of an operator input sequence and a selected terminal data stream, is identified at the terminal wherein such a selected combination will result in an incorrect representation in an optimizer presentation space memory of data stored in a terminal presentation space memory. In response to identifying the selected combination described above, terminal status data is added to the selected terminal data stream to create a modified terminal data stream, wherein the modified data stream includes information necessary for the optimizer to correctly represent in the optimizer presentation space memory data that is stored in the terminal presentation space memory. Next, the modified terminal data stream is sent to the optimizer, and the optimizer records data in the optimizer presentation space memory that represents data stored in the terminal presentation space memory. Next, the terminal status data is removed from the modified terminal data stream to recreate the selected terminal data stream in the optimizer. Finally, the optimizer sends the selected terminal data stream to the application running in the host computer, wherein the optimizer correctly maintains a record of data stored in the terminal presentation space memory.