Computers

Question 1

What is the input stage of the input-process-output?

Answer 1

Data is entered into the computer via input devices such as keyboard, mouse, microphone and camera.

Question 2

What is the process stage of the input-process-output?

Answer 2

The data is then processed. The computer performs a series of actions on the input data according to the instructions in the program it is following. This is done by the CPU in the processor.

Question 3

What is the output stage of the input-process-output?

Answer 3

The results of the processing are then output to the user of the computer through devices such as monitor, printer and speakers.

Question 4

What is the CPU?

Answer 4

The central processing unit carries out (executes) all of the stored program instructions.

Question 5

What is the CU of the CPU?

Answer 5

The control unit controls all of the other components of the CPU, it contains the decoder.

Question 6

What is the decoder of the CPU?

Answer 6

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

Question 7

What is the clock of the CPU?

Answer 7

Controls the rate at which program instructions are carried out, by sending control electrical signals at regular intervals, called cycles.

Question 8

What is the ALU of the CPU?

Answer 8

The arithmetic logic unit performs arithmetic and logical operations to carry out program instructions.

Question 9

What are the buses of the CPU?

Answer 9

They are electrical conductors that carry electrical signals between components in the CPU and between the CPU and other components in the motherboard.

Question 10

What are the registers of the CPU?

Answer 10

Memory locations. Some perform special functions in the fetch-decode-execute cycle.

Question 11

What is the cache of the CPU?

Answer 11

Very fast random access memory (RAM).

Question 12

What is clock speed measured in?

Answer 12

Gigahertz. 1 GHz is 10^9 cycles per second.

Question 13

What are the factors that affect the performance of the CPU?

Answer 13

Clock speed, cache size, number of cores and type of RAM, and hard drive speed.

Question 14

What is Von Neumann architecture?

Answer 14

The way in which the CPU is designed and carries out the instructions with other components.

Question 15

What did John Von Neumann do in 1945?

Answer 15

He designed a stored program computer where both the program and data are stored in the memory. The components are: a CPU, a program counter, memory and input and output mechanisms.

Question 16

What activities does the ALU carry out?

Answer 16

Addition, subtraction, multiplication and division. Comparisons between two different numbers.

Question 17

What is the program counter register?

Answer 17

Holds the address of the next instruction to be fetched.

Question 18

What is the MDR register?

Answer 18

The memory data register is a temporary store (buffer) for anything copied from memory.

Question 19

What is the MAR register?

Answer 19

The memory access register holds the address of the memory location currently being read (fetched) or written to.

Question 20

What is the accumulator register?

Answer 20

Stores the results of calculation carried out by the ALU.

Question 21

What happens during the fetch cycle of the fetch-decode-execute cycle?

Answer 21

The control unit sends a ‘read’ signal to the RAM on the control bus and uses the address bus to send signals specifying the required memory location in the RAM. The contents are transferred to the CPU along the data bus.

Question 22

What happens during the decode and execute of the fetch-decode-execute cycle?

Answer 22

The program instructions or data are sent from the RAM to the CPU. The CU interprets the instruction (decode). The CU then carries out the instruction. It instructs the ALU if calculations needs to be performed (execute).

Question 23

What is RAM?

Answer 23

Random access memory is where the computer stores data and instructions when an application is running. Data can be read from and written to RAM. It is volatile, meaning if power is turned off, the data in RAM is lost.

Question 24

What is ROM?

Answer 24

Read only memory is used to store instructions that don’t need to be changed during normal use. Data can only be read from ROM. ROM is non-volatile, it retains data even if the power is turned off.

Question 25

How can computers be upgraded with RAM?

Answer 25

As RAM is often removable, adding more RAM upgrades your computer.

Question 26

What is cache memory?

Answer 26

Cache memory is very fast memory, within the processor. The cache speeds up processing by storing recently or frequently used instructions so that they do not have to be fetched from the main memory which is much slower.

Question 27

What happens when the cache becomes larger?

Answer 27

It takes longer to find the data and becomes slower. Therefore, it is split into different levels.

Question 28

Why is cache not used for main memory in personal computers?

Answer 28

It is too expensive.

Question 29

What are the three main types of storage device?

Answer 29

Magnetic discs, optical discs and solid-state memory.

Question 30

What is the need for secondary storage?

Answer 30

Data and programs are stored permanently on secondary storage devices but the CPU cannot access them directly and so they must be transferred to the main memory. They can also be used to transfer stored data between computers.

Question 31

What is magnetic storage?

Answer 31

Magnetic storage devices include hard disc drives which can store large amounts of data. Hard disc drives consist of stacks of non-removable discs coated with magnetic materials.