Protected Mode - History

History

The Intel 8086, the predecessor to the 286, was originally designed with a 20-bit address bus for its memory. This allowed the processor to access 220 bytes of memory, equivalent to 1 megabyte. At the time, 1 megabyte was considered a relatively large amount of memory, so the designers of the IBM Personal Computer reserved the first 640 kilobytes for use by applications and the operating system and the remaining 384 kilobytes for the BIOS (Basic Input/Output System) and memory for add-on devices.

As the cost of memory decreased and memory use increased, the 1 MB limitation became a significant problem. Intel intended to solve this limitation along with others with the release of the 286.

Read more about this topic:  Protected Mode

Famous quotes containing the word history:

    No event in American history is more misunderstood than the Vietnam War. It was misreported then, and it is misremembered now.
    Richard M. Nixon (b. 1913)

    There is nothing truer than myth: history, in its attempt to “realize” myth, distorts it, stops halfway; when history claims to have “succeeded” this is nothing but humbug and mystification. Everything we dream is “realizable.” Reality does not have to be: it is simply what it is.
    Eugène Ionesco (b. 1912)

    All history is a record of the power of minorities, and of minorities of one.
    Ralph Waldo Emerson (1803–1882)