Scott David Mastie

Use of the transform exit sequence in printing and as a framework for the solution of complex problems

This paper is both a review of previous research and development and a description of new work for the IBM PSF/2 and PSF/6000 printing products. These products are best characterized as complex queue drivers, originally designed to allow fast printers to be driven directly from the existing print subsystems of OS/2® and AIX®, respectively. The new work extends the capability of these products by providing a framework that broadly redefines the way in which print queues can relate to printers, other queues, and other programs, without requiring any changes to the spooling system. This technical advance is based on the twin ideas of the transform exit and the transform exit sequence, which are examined in detail. Using this technology, both PSF/2 and PSF/6000 treat the largest mainframe-attached printers as local desktop printers, allowing LAN communities to print directly on mainframe printers from LAN applications. Other interesting uses of this technology include routing print jobs to the printers appropriate for their data types, improvements in printer throughput, automated print-job archiving, and improved system management, each of which is covered in some detail in the paper. Although some of these solutions can also be provided by extending the capabilities of the spooling systems and some have been addressed in particular environments and applications, the transform exit sequence framework does not depend on changes to the spooling system, allowing it to be used in a wide variety of current and future operating systems.