Abstract: A method and data processing system for emulating a program are disclosed. According to the present invention, the data processing system runs under a first operating system and emulates the execution of a program under a second operating system within a second data processing system. The data processing system includes a memory which stores at least a portion of the first operating system and an emulator comprising a plurality of routines which each emulate an instruction utilized by the first operating system. The memory further includes a simulated mass storage data area which stores at least a portion of the program and a simulated main memory data area. The data processing system further includes a processor which executes instructions within the program under the first operating system by emulation. According to the present invention, the emulator accesses instructions of the program directly from the simulated mass storage data area to minimize emulation overhead.

Abstract: A method and data processing system for emulating a program are disclosed. According to the present invention, the data processing system runs under a first operating system and emulates the execution of a program under a second operating system within a second data processing system. The data processing system includes a memory which stores at least a portion of the first operating system and an emulator comprising a plurality of routines which each emulate an instruction utilized by the first operating system. The memory further includes a simulated mass storage data area which stores at least a portion of the program and a simulated main memory data area. The data processing system further includes a processor which executes instructions within the program under the first operating system by emulation. According to the present invention, the emulator accesses instructions of the program directly from the simulated mass storage data area to minimize emulation overhead.

Abstract: The disclosed data stream optimization process is containing two logical entities, the first being the pre-comparison optimizer component and the second being the comparison component. The pre-comparison optimizer component performs two discrete tasks. First, the input data stream is written into a next state buffer. Second, the elimination of redundancies involves detecting and removing redundant screen attributes, since the terminal's execution time for processing a screen attribute is more than that required for a data character. The comparison component contains three distinct sub-components. First, non-data constructs such as commands and orders are optimized and placed in the outgoing data stream. Second, the screen image that is represented by the data stream is compared to the existing screen image to further reduce the outgoing data stream.