A quick look at the pinouts of an Intel 8086 & 8088 processor reveals a 20 bit address bus. There was high demand for the ability to address 1 meg (2^20) of address space, and Intel delivered.

Virtual 8086 Mode divides the computer into multiple address spaces and maintains registers for each one. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

Few CPUs have had the long-lasting influence that the 8086 did. It is hard to believe that when your modern desktop computer boots, it probably thinks it is an 8086 from 1978 until some software ...