How to use Dos box ?and what is emulator -wht is difference between object file and text file

Описание: Before Windows XP, consumer-oriented versions of Windows were based on MS-DOS. Windows 3.0 and its updates were operating environments that ran on top of MS-DOS, and the Windows 9x series consisted of operating systems that were still based on MS-DOS.[6] These versions of Windows could run DOS applications. Conversely, the Windows NT operating systems were not based on DOS. A member of the series, Windows XP, debuted on October 25, 2001, and became the first consumer-oriented version of Windows to not use DOS. Although Windows XP could emulate DOS, it could not run many of its applications as they ran only in real mode to directly access the computer's hardware, and Windows XP's protected mode prevented such direct access for security reasons.[7][8] MS-DOS continued to receive support until the end of 2001,[9] and all support for any DOS-based Windows operating system ended on July 11, 2006.[10]

The development of DOSBox began around the launch of Windows 2000—a Windows NT system[11]—when its creators,[12] Dutch programmers Peter Veenstra and Sjoerd van der Berg, discovered that the operating system had dropped much of its support for DOS software. The two knew of solutions at the time, but they could not run the applications in windowed mode or scale the graphics. The project was first uploaded to SourceForge and released for beta testing on July 22, 2002.[13]