cls (for clear screen) is an MS-DOS command used to clear the screen of commands and any output generated by them. It does not clear the user's history of commands, however. In most other environments, like for instance Linux and Unix the same functionality is provided by the clear command. Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ... Linux (IPA pronunciation: ) is a Unix-like computer operating system. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®) is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ... Clear being used on GNU/LInux under uxterm This article or section does not adequately cite its references or sources. ...

While the ultimate origins of using the three-character string cls as the command to clear the screen likely predate Microsoft's use, this command was present before its MS-DOS usage, in the embedded ROM BASIC dialects Microsoft wrote for early 8-bit microcomputers (such as TRS-80 Color BASIC), where it served the same purpose. The MS-DOS dialects of BASIC written by Microsoft, BASICA and GW-BASIC, also have the cls command as a BASIC keyword. The cls command is not present in the BASIC versions for Microsoft Windows (such as Visual Basic) where clearing the screen does not make sense because the program's user interface is managed by the operating system while the program runs. Screenshot of Atari BASIC, an early BASIC language for small computers. ... This article or section does not cite its references or sources. ... Color BASIC is the implementation of Microsoft BASIC that is included in the ROM of the Tandy/Radio Shack TRS-80 Color Computers (CoCos) manufactured between 1980 and 1991. ... Microsoft BASICA (short for Advanced BASIC) is a simple disk-based BASIC interpreter written by Microsoft for PC-DOS. BASICA allows use of the ROM_resident BASIC on the PC while DOS is loaded (the ROM BASIC itself runs when nothing is loaded when booting) and adds functionality such as file... GW-BASIC 3. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... Visual Basic (VB) is an event driven programming language and associated development environment from Microsoft for its COM programming model. ...

The command cls has appeared as a clear screen command in many other BASIC dialects and command interpreters, because of its familiarity through being included in MS-DOS.