sentences:  The BIOS improved the coexistence of DR-DOS with Windows 9x and its support for third-party disk compression drivers such as Microsoft's DriveSpace.It introduced a diagnostics mode (activated by Scroll Lock), integrated debugger support (with DEBUG=ON and a debugger loaded before or from within CONFIG.SYS) and more flexible CONFIG.SYS tracing capabilities via the /// hotkeys and the TRACE and TIMEOUT commands, thereby also improving the integration of alternative command line shells such as 4DOS.Together with LOADER, SYS /DR