Address Windowing Extensions

Address Windowing Extensions (AWE) is a software interface in the Microsoft Windows operating system that allows a 32-bit application to access memory that is larger than the available virtual address space (2-3 gigabytes). The process of displaying additional memory in the address space of an application using AWE is called "windowing" (window access) and is similar to the concept of "overlay" used, for example, in DOS. AWE is suitable for applications that handle large amounts of data, such as DBMS, scientific and engineering applications. The application allocates a memory region called a window in the virtual address space and requests the allocation of one or more regions of physical memory using the interface. Later, the interface allows the application to map any selected region of physical memory to a window in the address space. It is possible to create several windows, so that the total size of the windows does not exceed the size of the available virtual address space. The sizes of windows and regions of physical memory can be arbitrary (multiple memory page size, 4096 bytes), but on any of the windows it is possible to display the region of physical memory that does not exceed the size of the window. Address Windowing Extensions