Systems ArchitectureIntroduction
The Bookmark and the Whiteboard
Part of Program Counter & Accumulator — GCSE Computer Science
This introduction covers The Bookmark and the Whiteboard within Program Counter & Accumulator for GCSE Computer Science. Revise Program Counter & Accumulator in Systems Architecture for GCSE Computer Science with 15 exam-style questions and 12 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 1 of 7 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 1 of 7
Practice
15 questions
Recall
12 flashcards
The Bookmark and the Whiteboard
Imagine you're reading a recipe book while cooking. You use a bookmark to keep track of which step you're on (that's the Program Counter - always pointing to the next instruction). Meanwhile, you write calculation results on a whiteboard next to you (that's the Accumulator - storing intermediate results). Just as you move the bookmark down one step after reading each instruction, the PC increments after each fetch. And just as you erase and rewrite on the whiteboard with each new calculation, the ACC updates with each ALU operation.