Which of the following methods does NOT alter the address before it is used?

• A. Indexed Addressing
• B. Direct Addressing
• C. Immediate Addressing
• D. Indirect Addressing

Answer: (B)

In direct addressing, the address specified in the instruction is used exactly as it appears without any modification. This means that the instruction points directly to the location in memory where the data is stored. Consequently, the processor retrieves data from that exact address without needing any further calculations, transformations, or alterations.

In contrast, indexed addressing modifies the address by adding an index value to a base address to reach the final address. Immediate addressing does not refer to a memory address at all, but instead uses a constant value directly within the instruction. Indirect addressing involves first accessing a memory location to obtain the actual address where the data resides, thus changing the address that the instruction ultimately uses.

Direct addressing serves a specific purpose where simplicity and speed are paramount, as the address used is straightforward and unaltered, making it very efficient for scenarios where the memory location is known and fixed.