This section contains a description of the internal underlying software structure for operating systems, subsystems, and application programs. These sections are patterned on presentations that I have given to various design groups and seminars during the time I was employeed at IBM. A PowerPoint version of the System Infra-Structure presentation can be viewed by clicking PowerPoint  View

I will try to keep this description in a narrative style to keep it interesting but please forgive me if I lapse into a dry report style every once in a while. At this time I will provide text and some graphics to help visualize these concepts. Full graphics are provided in the PowerPoint presentation.

All of these concepts are detailed in an IBM Technical Report published in July 1992.

  • System Infra-Structure for Software by James Lum
  • TR 03.443
  • Santa Teresa Laboratory, San Jose, California

    Even though all of these ideas and concepts came to fruition before the introduction of OOPs, they are still applicable today because they address the underlying structure of the software implementation itself.

    The ideas and concepts were completed during 1972 thru 1976 and resulted in the implementation of an operating system, Systems Assurance Kernal (SAK), and a family of application programs used primarily for testing new IBM mainframe architecture and its implementaton by IBM Engineering. SAK is currently still in use today, internally, at IBM.

    These concepts were successfully implemented in both the above software and in existing applications that ran under other operating systems. In these existing applications, only structural changes were made since the functions were already defined and working. These modified applications required less storage, were faster, and had new capabilities due to the ease of recursion. They also took less time to build and had improved runtime performance.