Address space sizing With an 8-bit address code, how many unique memory locations can be selected?

Introduction / Context:
Address lines select locations in memory using binary codes. The number of unique addresses depends on the number of address bits. This is a foundational calculation in digital design and computer architecture.

Given Data / Assumptions:

• Number of address bits n = 8.
• Each unique address maps to one location.
• Binary combinations are counted as powers of 2.

Concept / Approach:

The number of unique codes represented by n bits is 2^n. Therefore, an 8-bit address field can address 2^8 locations. This relationship scales directly (e.g., 16 bits → 2^16 locations, etc.).

Step-by-Step Solution:

Verification / Alternative check:

Check extremes: with 1 bit you can select 2 locations; doubling bits squares capacity. 8 bits yielding 256 is consistent with this rule.

Why Other Options Are Wrong:

• 8 locations: corresponds to 3 address bits.
• 65,536 locations: requires 16 address bits.
• 131,072 locations: requires 17 address bits.

Common Pitfalls:

• Confusing bytes of data per location with number of locations. Address bits count locations, independent of data width.

Final Answer:

256 locations in memory