Topic summary
Upper memory
Extracted from the Wikipedia article Upper memory area.
Virtual 8086 Mode
Upper memory blocks can be created by mapping extended memory into the upper memory area when running in virtual 8086 mode. This is similar to how expanded memory can be emulated using extended memory so this method of providing upper memory blocks is usually provided by the expanded memory manager (for example EMM386). The application programming interface for managing the upper memory blocks is specified in the eXtended Memory Specification.