As an example, the 6800 included a special "direct" addressing mode that was used to make code smaller and faster; instead of a memory address having 16-bits and thus requiring two bytes to store, direct addresses were only 8-bits long. The downside was that it could only refer to memory within a 256-byte window, the "direct page", which was normally at the bottom of memory - the 6502 referred to this as "zero page addressing" instead. The 6809 added a new 8-bit DP register, for "direct page". Code that formerly had to be in the zero page could now be moved anywhere in memory as long as the DP was changed to point to its new location.