Computer Science GCSE - OCR Paper 1

Computer Science GCSE - OCR Paper 1
What makes a computer a computer? - ANS Input - Process/Storage - Output



Diagram of Von Neumann Architecture - ANS



What does HTML stand for? - ANS Hypertext Markup Language



What is the CPU made up of? - ANS Control Unit (CU)

Arithmetic Logic Unit (ALU)

Cache

Registers



What does the CU do? - ANS Tells everything else what to do



What does the ALU do? - ANS It carries out all the arithmetic and logical operations such as addition.
subtraction and logical operations



What is cache? - ANS Very Small, Very fast memory for frequently used info near the CPU



What registers are there? - ANS Accumulator (Acc)

Program Counter (PC)

Memory address register (MAR)

Memory Data Register (MDR)



What does the accumulator do? - ANS Stores intermediate results of calculations in the ALU

,What does the program counter do? - ANS Holds the memory address of the instruction for each cycle



What does the memory address register do? - ANS Holds any memory address about to be used by the
CPU



What does the memory data register do? - ANS Temporarily stores the data that has just been read from
or the data needs to be written.



What does the CPU do? - ANS processes data (fetch -> decode -> execute -> repeat)



CPU fetches next instruction from RAM, decodes it can carries it out



What is the speed of a CPU measured in - ANS Hz (or more commonly GHz)



What are the main factors effecting the speed of the CPU? - ANS - Size of the Cache

- Number of cores (programs have to be written to make use of the cores)

- The clock speed. Overclocking can be done by increasing the voltage going to the CPU



What is the purpose of an embedded system - ANS to control the device and to allow a user to interact
with it



Examples of Embedded Systems - ANS Microwave Ovens

Washer-dryers

Car dashboards

Calculators

Sat-Navs

, Digital Cameras



List the three types of storage - ANS Primary storage

Secondary Storage

Tertiary Storage



Give examples of Primary Storage - ANS RAM

ROM

Register

Cache



Give examples of Secondary Storage and what might be stored on it - ANS HDD/SSD

The OS

Programs

Data



What might tertiary Storage be for - ANS backups/archives of large amounts of data



Features of Primary Storage - ANS - ROM is read-only

- All others are volatile

- Relatively small capacity compared to secondary (GBs)

- Very Fast Access time



Features of Secondary Storage - ANS - Non-Volatile

- Much Larger Capacity (TBs)