8085 bit-rotation as multiplication: Using the RAL (Rotate Accumulator Left through Carry) instruction, how many RAL operations are needed to multiply an 8-bit unsigned value by 8?

Introduction / Context:
Left shifts on binary integers multiply by powers of two. On the 8085, arithmetic left shift is not a single instruction, but RAL (rotate left through carry) effectively shifts left by one bit when used carefully, enabling multiplication by 2^n.

Given Data / Assumptions:

• Instruction RAL rotates the accumulator left through the carry flag by 1 bit.
• We are multiplying an unsigned value by 8 (which is 2^3).
• Overflow and carry handling are the programmer’s responsibility.

Concept / Approach:
Each left shift by one bit multiplies the binary number by 2. Therefore, to multiply by 8, we need three successive left shifts. On 8085, three RAL operations can be used in sequence to achieve this, provided we account for carry if needed.

Step-by-Step Solution:

Verification / Alternative check:
Test with a small value, e.g., A=0000 0011 (3). After three RALs (ignoring overflow), we get 0001 1000 (24) which is 3*8.

Why Other Options Are Wrong:

Common Pitfalls:

Final Answer: