Windows 3.x

This is a graphics-based operating environment from Microsoft. This operating system runs under DOS. Thus, it is usually called "DOS with windows." Windows 3.x allows multiple tasking, allowing users to open several applications simultaneously and shift between them. Windows operating system is very similar to the Macintosh desktop environment.
Windows 3.x is a major upgrade of Microsoft's earlier versions. It provides a DOS extender that allows Windows 3.x applications to run in up to 16MB of memory. In the Windows, users can run DOS applications and change data between them.

Modes

Windows 3.x has three different operating modes.

• Real Mode: This mode is for computers with less than 1MB of memory. It uses expanded memory if available, and does not use extended memory.

• Standard Mode: This is a normal Windows 3.0 operating mode. It works with extended memory (XMS). This mode allows users to use DOS applications in the window environment by allowing users to switch between DOS applications and windows applications. The mode also uses expanded memory (EMS) if available.

• 386 Enhanced Mode: This mode is the extension of Windows/386 version that runs on 386 and higher CPUs. This mode allows multitasking of Windows and standard DOS applications. It converts character-based programs (DOS applications) to bit-mapped graphics (Windows applications). It activates EMM386.SYS memory manager to use EMS memory.

Advantages and Disadvantages

• Advantages: Windows allows multitasking capability and more primary memory. Windows provides a memory manager to allow users to access more than 640KB of conventional memory. Another benefit of it is that it has a dynamic data exchange function. Dynamic data exchange allows one program (e.g., a word processing program) to request data or information from other programs (e.g., a spreadsheet program or a database program etc.) currently running and use those information. A graphical user interface (GUI) against character- based approach is another advantage. This allows users to use Windows environment such as mouse, pointer, clicking, icon, or pull-down menu.

• Disadvantages: Windows 3.x can handle multitasking, but it is really switching between tasks. Windows 3.x is not a multithreaded operating system. This works well for many applications, but for some information and data can be lost if Windows does not get back to a task soon enough. There are many application programs for Windows, but users frequently demand more powerful application programs that exceed the capabilities of current Windows programs. The other disadvantage is that Windows 3.x was not originally intended for networks and is not very efficient in that environment although it has a network version, Windows for Workgroup 3.11.

Window

A window was originally a general name of viewing area on a display screen provided by software. Many operating systems can provide multiple windows on a display screen. Under this environment, users usually can work several tasks with several application programs on a screen at the same time. Microsoft makes Windows the brand name of its operating system. They are Windows/286, Windows/386, Windows 3.x, Windows 95 and Windows NT. Users need to be careful not to think of only Microsoft's Windows has windows. Many operating systems such as OS/2 Presentation Manager, OS/2 WARP, many UNIX systems, and Macintosh operating system have windows.

XMS

It is an abbreviation of eXtended Memory Specification. This is an interface that allows DOS applications to use extended memory. This allows DOS applications to only allocate extended memory, but does not allow them to run in extended memory.

EMS

Expanded Memory Specification is a technique for expanding memory beyond one megabyte under DOS. EMS and XMS are different techniques to enlarge memory running under DOS. XMS is a normal memory beyond one megabyte on 286 and higher computers, but EMS is separate memory that can be installed in any computer system.