Presentation Manager
Presentation Manager (PM) is the graphical user interface (
in late 1988.History
Microsoft began developing a
One of the most significant differences between Windows and PM was the coordinate system. While in Windows the 0,0 coordinate was located in the upper left corner, in PM it was in the lower left corner. Another difference was that all drawing operations went to the Device Context (DC) in Windows. PM also used DCs but there was an added level of abstraction called Presentation Space (PS). OS/2 also had more powerful drawing functions in its Graphics Programming Interface (GPI). Some of the GPI concepts (like viewing transforms) were later incorporated into Windows NT. The OS/2 programming model was thought to be cleaner, since there was no need to explicitly export the window procedure, no WinMain, and no non-standard function prologs and epilogs.
Parting ways
One of the most-cited reasons for the IBM-Microsoft split was the divergence of the
In 1990, version 3.0 of Windows was beginning to sell in volume, and Microsoft began to lose interest in OS/2 especially since, even earlier, market interest in OS/2 was always much smaller than in Windows.
The companies parted ways, and IBM took over all of subsequent development. Microsoft took OS/2 3.0, which it renamed Windows NT; as such, it inherited certain characteristics of Presentation Manager. IBM continued to develop Presentation Manager. In subsequent versions of OS/2, and derivatives such as ArcaOS, it was used as a base for the object-oriented interface Workplace Shell.
There is a significant integration of the GUI layer with the rest of the system, but it is still possible to run certain parts of OS/2 from a text-console or X window, and it is possible to boot OS/2 into a command-line environment without Presentation Manager (e.g. using TSHELL[4] ).
Presentation Manager for Unix
In the late 1980s,
Technical details
PM follows the
An important problem was that of the single input queue: a non-responsive application could block the processing of user-interface messages, thus freezing the graphical interface. This problem has been solved in Windows NT, where such an application would just become a dead rectangle on the screen; in later versions it became possible to move or hide it. In OS/2 it was solved in a FixPack, using a timer to determine when an application was not responding to events.
See also
References
- ^ a b Alsop, Stewart II (1988-01-18). "Microsoft Windows: Eclectism in UI" (PDF). P.C. Letter. 4 (2): 6–7.
- ^ Miller, Michael J. (April 1987). "IBM's OS/2 to Become Operating System of Choice, but Not for Some Time". InfoWorld: 46.
- ^ Vellon, Manny (1987). "OS/2 Windows Presentation Manager". Microsoft Systems Journal. 2 (2).
- ^ "TSHELL non-GUI shell for OS/2". Retrieved 17 April 2011.
- ^ Bob Ponting (1988-11-21). "Unix PM Scheduled for 2nd Quarter". InfoWorld. Retrieved 2021-12-29.
- ^ Martin Marshall; Ed Scannell (1988-10-10). "OSF Narrows Its Search For User Interface to 23". InfoWorld. p. 45. Retrieved 2021-12-29.
- ^ Janet Dobbs (August 1989). "Strategies for Writing Graphical UNIX Applications Productively and Portably" (PDF). AUUG Newsletter. 10 (4): 50. Retrieved 2021-12-29.
- ^ Axel O. Deininger; Charles V. Fernandez (June 1990). "Making Interface Behavior Consistent: The HP OSF/Motif Graphical User Interface" (PDF). Retrieved 2021-12-29.
- ^ Mace, Scott (20 February 1989). "Microsoft Says It Will Purchase Portion Of SCO". InfoWorld. p. 5. Retrieved 3 January 2024.
- ^ Stuart J. Johnson (January 1989). "HP, Microsoft to Continue Development of Alternate API". InfoWorld. p. 38. Retrieved 2021-12-29.
External links
- IBM Corporation (Oct 1994). Presentation Manager Programming Guide: The Basics (PDF). Retrieved 28 April 2017.
- IBM Corporation (Oct 1994). Presentation Manager Programming Guide: Advanced Topics (PDF). Retrieved 28 April 2017.
- IBM Corporation (Oct 1994). Presentation Manager Programming Reference Volume 1 (PDF). Retrieved 28 April 2017.
- IBM Corporation (Oct 1994). Presentation Manager Programming Reference Volume 2 (PDF). Retrieved 28 April 2017.