RAM vs. ROM fundamentals: The key differences between random access memory (RAM) and read-only memory (ROM) are that ________.

Introduction / Context:
Understanding the practical differences between RAM and ROM is foundational in digital systems. Designers choose between these technologies based on mutability, volatility, and how the memory connects to buses and control signals. This question asks which statements correctly distinguish RAM from ROM in typical systems.

Given Data / Assumptions:

• RAM refers to volatile semiconductor memory (e.g., SRAM, DRAM) that supports read and write operations.
• ROM refers broadly to non-volatile memory (mask ROM, PROM/OTP, EPROM, EEPROM, Flash) that is read-mostly during normal operation.
• Both RAM and ROM are randomly addressable; neither inherently requires sequential access like tape.

Concept / Approach:
During normal operation, RAM exposes a read/write control (often WE for write enable) that permits frequent updates. ROM devices, by contrast, either cannot be altered or require special programming procedures, so a normal read/write control for everyday writes is absent. RAM loses its contents at power-down (volatile), while ROM retains data (non-volatile). Addressing for both is random: any valid address can be accessed in roughly constant time.

Step-by-Step Solution:

Verification / Alternative check:
Datasheets for SRAM/DRAM show WE and volatile storage; ROM/Flash parts document read-mostly operation and data retention across power cycles.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming “random access” means “RAM only,” or thinking ROM must be read sequentially.

Final Answer:
RAM has a read/write signal and ROM doesn't; RAM will lose data when the power is removed and ROM won't.