The Intersil 80C286/883 is a static CMOS version of theNMOS 80286 microprocessor. The 80C286/883 is anadvanced, high-performance microprocessor with speciallyoptimized capabilities for multiple user and multi-tasking systems.The 80C286/883 has built-in memory protection thatsupports operating system and task isolation as well as programand data privacy within tasks. The 80C286/883includes memory management capabilities that map 230(one gigabyte) of virtual address space per task into 224bytes (16 megabytes) of physical memory.The 80C286/883 is upwardly compatible with 80C86 and80C88 software (the 80C286/883 instruction set is a supersetof the 80C86/80C88 instruction set). Using the 80C286/883 real address mode, the 80C286/883 is object code compatiblewith existing 80C86 and 80C88 software. In protectedvirtual address mode, the 80C286/883 is source codecompatible with 80C86 and 80C88 software but may requireupgrading to use virtual address as supported by the80C286/883’s integrated memory management and protectionmechanism. Both modes operate at full 80C286/883performance and execute a superset of the 80C86 and80C88 instructions.The 80C286/883 provides special operations to support theefficient implementation and execution of operating systems.For example, one instruction can end execution of one task,save its state, switch to a new task, load its state, and startexecution of the new task. The segment-not-present exceptionand restartable instructions.