Editing Protected mode (section)

==== Real mode ====
In real mode each logical address points directly into a physical memory location, every logical address consists of two 16-bit parts: The segment part of the logical address contains the base address of a segment with a granularity of 16 bytes, i.e. a segment may start at physical address 0, 16, 32,&nbsp;..., 2<sup>20</sup>&nbsp;−&nbsp;16. The offset part of the logical address contains an offset inside the segment, i.e. the physical address can be calculated as physical_address = segment_part × 16 + offset, if the address [[A20 line|line A20]] is enabled, or (segment_part × 16 + offset) mod 2<sup>20</sup>, if A20 is off.{{Clarify|date=August 2011}} Every segment has a size of 2<sup>16</sup>&nbsp;bytes.