Writing a 16-bit Custom Control for Windows 95/98/Me
Operating systems are becoming faster, powerful, and reliable every day and Microsoft has been a forerunner in this. From the humble beginnings of MS-DOS and Windows 3.l Microsoft have raised the PC platform to a new level with its Windows 95. Increasing the ease of use and power over it predecessors Windows 95 is the beginning of a new breed of operating system like Window 98 and Windows Me, Also sometime collectively referred to as Windows 9x. Windows 95 is also one of the first Microsoft operating system that was developed for 32-bit applications.
While it is certainly worth exploring the new and exciting features of these operating systems it is also equally important to see what they offer in terms of new features and improved performance for legacy applications. We will now try to understand Windows 9x operating systems in detail especially from the point of view of a legacy 16-bit application written for Windows 3.1. We will also discuss in detail a real-time 16-bit application, which needs to take advantage of one of the features available for 32-bit based applications. As a reference we will use Window 98 as the reference architecture to understand Windows 9x operating system family.
Windows 98 is a 32-bit operating system. It has a complete 32-bit kernel, which includes memory management, preemptive multitasking and multithreading support. The diagram below shows the various components of the system. The ones in color are the ones that we will be discussing in detail as they have the responsibility of running 16-bit applications in the operating system.
