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Addressing mode
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===Direct page=== The zero page address mode was enhanced in several late model 8-bit processors, including the [[WDC 65816]], the [[CSG 65CE02]], and the [[Motorola 6809]]. The new mode, known as "direct page" addressing, added the ability to move the 256-byte zero page memory window from the start of memory (offset address $0000) to a new location within the first 64 KB of memory. The CSG 65CE02 allowed the direct page to be moved to any 256-byte boundary within the first 64 KB of memory by storing an 8-bit offset value in the new base page (B) register. The Motorola 6809 could do the same with its direct page (DP) register. The WDC 65816 went a step further and allowed the direct page to be moved to any location within the first 64 KB of memory by storing a 16-bit offset value in the new direct (D) register. As a result, a greater number of programs were able to utilize the enhanced direct page addressing mode versus legacy processors that only included the zero page addressing mode.
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