Windows 3.0 succeeded Windows 2.1x and included a significantly revamped user interface as well as technical improvements to make better use of the memory management capabilities of Intel's 80286 and 80386processors. Text-mode programs written for MS-DOS could be run within a window (a feature previously available in a more limited form with Windows/386 2.1), making the system usable as a crude multitasking base for legacy programs. However, this was of limited use for the home market, where most games and entertainment programs continued to require raw DOS access.[2]
The MS-DOS Executive file manager/program launcher was replaced with the icon-based Program Managerand the list-based File Manager, splitting files and programs. The Control Panel, previously available as a standard-looking applet, was re-modeled after the one in Mac OS. It centralized system settings, including limited control over the color scheme of the interface.[3]
A number of simple applications were included, such as the text editor Notepad and the word processor Write (both inherited from earlier versions of Windows), a macro recorder (new; later dropped), the paint program Paintbrush (inherited but substantially improved), and a calculator (also inherited). Also, the earlier Reversigame was complemented with the card game Solitaire.[3]
The Windows icons and graphics support a full 16 colors in EGA and VGA mode while Windows 2.x had only a very limited palette for colored menus and window boxes with in-application graphics being monochrome. 256-color VGA mode was supported for the first time.
Windows 3.0 includes a Protected/Enhanced mode which allows Windows applications to use more memory in a more painless manner than their DOS counterparts could. It can run in any of Real, Standard, or 386 Enhanced modes, and is compatible with any Intel processor from the 8086/8088 up to 80286 and 80386.[4]Windows 3.0 tries to auto detect which mode to run in, although it can be forced to run in a specific mode using the switches: /r (real mode), /s ("standard" 286 protected mode) and /3 (386 enhanced protected mode) respectively.[5] Since Windows 3.0 (and later Windows 3.1) runs in 16-bit 286 protected mode and not 32-bit 386 protected mode, the default setup is to use the 64 KB segmented memory model. However, on 32-bit CPUs, the programmer had access to larger memory pointers and so it was possible to expand program segments to whatever size was desired (the maximum limit being 16 MB due to segment descriptors being 24-bit). Since Windows API functions were 16-bit at the time, they could not use 32-bit pointers and thus it was necessary to place the portion of the program code that performed OS calls in a 64 KB segment,[6] like in DOS, although 32-bit instructions may be contained in the code.[7] (Ami Pro was the first Windows application to require a 386). Because of this, Windows 3.0 can access only 16 MB total of RAM, even on 386 or higher CPUs which have a theoretical capability of utilizing 4GB.
This was the first version to run Windows programs in protected mode, although the 386 enhanced mode kernel was an enhanced version of the protected mode kernel for Windows/286.
-Wikipedia
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