Real mode, also called real address mode, is an operating mode of all x86-compatible CPUs Real mode is characterized by a 20 bit segmented memory address space (giving exactly 1 MiB of addressable memory) and unlimited direct software access to all memory, I/O addresses and peripheral hardware. Real mode provides no support for memory protection, multitasking, or code privilege levels. Before the release of the 80286, which introduced Protected mode, real mode was the only available mode for x86 CPUs. In the interests of backwards compatibility, all x86 CPUs start in real mode when reset.
Read more about Real Mode: History, Addressing Capacity, A20 Line, Switching To Real Mode
Famous quotes containing the words real and/or mode:
“One’s real life is so often the life that one does not lead.”
—Oscar Wilde (1854–1900)
“Yours of the 24th, asking “the best mode of obtaining a thorough knowledge of the law” is received. The mode is very simple, though laborious, and tedious. It is only to get the books, and read, and study them carefully.... Work, work, work, is the main thing.”
—Abraham Lincoln (1809–1865)