OCR GCSE Computer Science Revision Paper 1- Saim C :D

State the purpose of the CPU.

• Contains the CU

• Executes all of the stored program instructions

• Contains registers

• Interprets instructions

Define the purpose of the CU

• Controls all the other components of the CPU.

• Interprets program instructions and tells the ALU what operations to carry out

• Electrical conductors

• A very fast RAM

Define the purpose of the ALU

• Controls the flow of data

• A simple memory location stored within the CPU which helps with the storage of application software

• Performs the arithmetic and logical operations to carry out program instructions

• Controls what rate instructions are executed.

What is the clock?

• The time between a input such as a key being pressed and the output of the key being presented.

• The time taken to send a packet across a network

• The time taken for a router to connect to the internet

• Controls the speed at which program instructions are carried out, by sending control electrical signals at regular intervals,AKA cycles

Define the purpose of the decoder.

• Used to find bugs in the PC to ensure the PC runs smoothly and at its best performance

• To translate the instructions and tells the other components, ALU what operations to carry out

• Executes logical operations and arithmetic operations.

• To transport instructions around the motherboard

How does a bus transport data across the motherboard.

• Electrical conductors that carry electrical signals between components.

• A bus is a little wire which passes on instructions by the internet

What is clock speed?

• How many clock cycles can be performed within a second.

• The GHz

• How many instructions can be carried in 1 second.

• The speed of how quickly a PC is able to respond to inputs.

Which is not located in the CPU?

• RAM

• Mouse

• CU

• Fan

Which of the following is an example of 'main memory'.

• Hard Drive

• USB Drive

• RAM

• ROM

Role of the MDR?

• Temporary store buffer

• Stores result from ALU

• Holds address of the memory currently being read or read from

• Holds the address of the next instruction to be fetched