In DOS memory management, expanded memory is a system of bank switching that offered additional memory to DOS programs past the limit of typical memory (640 KiB). Expanded memory is an umbrella time period for a number of incompatible technology variants. The most widely used variant was the Expanded Memory Specification (EMS), which was developed jointly by Lotus Software program, Intel, and Microsoft, in order that this specification was sometimes known as “LIM EMS”. LIM EMS had three variations: 3.0, 3.2, and 4.0. The first broadly implemented model was EMS 3.2, which supported up to 8 MiB of expanded memory and makes use of elements of the deal with house usually devoted to communication with peripherals (upper memory) to map portions of the expanded memory. EEMS, an expanded-memory administration normal competing with LIM EMS 3.x, was developed by AST Analysis, Quadram and Ashton-Tate (“AQA”)