Real Mode: An operating mode that Windows runs in to provide maximum compatibility with versions of Windows applications prior to 3.0. Real mode is the only mode available for computers with less than 1MB of extended memory.
Real mode is equivalent to previous versions of Windows (2.x), and can address 640KB of conventional memory, plus LIM EMS Version 4.0 expanded memory. Extended memory can be used for a virtual disk or disk caching only.
Real mode requires an 8088 processor or above, and 640KB of installed memory. Real mode requires 384KB of free conventional memory after DOS and other memory resident software, including network drivers, is loaded.
Real mode is supported for Windows and its applications under OS/2 Version 2.0, in either of two ways:
Note that the commercially available Windows product cannot be run in standard or enhanced modes in a VDM due to Windows' memory management architecture; Windows assumes that it is a DPMI host and cannot act as a DPMI client. Many Windows applications run quite adequately in real mode; in fact, some applications written for Windows 2.x cannot run in any other mode.