A Level Computer Science OCR Practice Exam

Which instruction in LMC is responsible for storing the accumulator's value?

1. LDA

2. Bra

3. STA

4. BRZ

The correct answer is: STA

The instruction responsible for storing the accumulator's value in the Little Man Computer (LMC) architecture is indeed STA, which stands for "Store Accumulator." This instruction takes the value currently held in the accumulator and writes it into a specified memory location. When you use the STA instruction, it effectively allows data to be saved for later use, making it a fundamental operation in any computational process where results need to be preserved in memory. This capability is crucial for tasks such as maintaining state between calculations or retrieving stored information for further processing. Other instructions in LMC serve different purposes: LDA is used to load a value from memory into the accumulator, Bra is a branch instruction that directs the program to jump to a different address, and BRZ is a conditional branch instruction that transfers control depending on whether the accumulator value is zero. These functionalities are important in program flow but do not involve the storage of the accumulator's value directly.