This exam tips covers Exam Tips - MAR and MDR within MAR & MDR for GCSE Computer Science. Revise MAR & MDR in Systems Architecture for GCSE Computer Science with 15 exam-style questions and 10 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 7 of 7 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 7 of 7
Practice
15 questions
Recall
10 flashcards
Exam Tips - MAR and MDR
The golden rule:
- MAR = Address = WHERE = Address Bus
- MDR = Data = WHAT = Data Bus
Common mistakes to avoid:
- Mixing up MAR and MDR - this loses ALL marks for that question!
- Forgetting which bus each connects to
- Saying MAR holds data or MDR holds addresses
Top tip: If you're ever unsure, think "Address before Data" - MAR works first (says where), then MDR receives the result (the data).