Components of a Computer

Question 1

Computer:

Answer 1

an electronic device for storing and processing data, typically in binary form, according to instructions given to it in a variable program

Question 2

Some typical inputs in a Supermarket:

Answer 2

Barcode Scanner
Touch Screen
Chip and Pin Device
Magnetic Strip Reader
Keypad
Keyboard
Scales
Portable Bracode Scanner

Question 3

Some typical outputs in a Supermarket:

Answer 3

Monitors
Display for the Customer
Receipt Printer

Question 4

Hardware

Answer 4

Objects that you can touch

E.g. a music CD, disks, disk drives, display screens, keyboards, printers, boards, chips etc.

Question 5

Software

Answer 5

You cannot ‘touch’ software.
Software refers to the programs that run on a computer.
E.g. Windows, MS Word, MS Excel, Kodu, Logo etc.

Question 6

What does the CPU do?

Answer 6

Fetch – Decode – Execute cycle
• The computer has a list of instructions in memory to carry out:
• CPU Fetches top instruction from the list
• Instructions are passed to Decoder to interpret
• Decoder passes on the instruction
• Each instruction is Executed or carried out

Question 7

Processor speed
1 Hertz (Hz) =
1 Kilohertz (kHz) = 
1 Megahertz (MHz) =
1 Gigahertz (GHz) =

Answer 7

= One cycle per second = 1 instruction carried out each second
= 1000 cycles per second
= 1,000,000 cycles per second
= 1,000,000,000 (1 Billion) cycles per second

Question 8

What is memory?

Answer 8

Computer memory is any physical device capable of storing information temporarily, like RAM (random access memory), or permanently, like ROM (read-only memory).

Question 9

RAM

Answer 9

• stands for random access memory
• RAM is volatile (contents lost when turned off) memory that temporarily stores the files you are working on
• large in comparison to ROM
• holds the operating system, programs and data I use by the CPU when the computer is running

Question 10

ROM

Answer 10

• stands for read-only memory, are both present in your computer
• ROM is non-volatile (contents remain when turned off) memory that permanently stores instructions for your computer
• small piece of memory on the mega board
• contains the first instructions (bootstrap) for the computer to check if the hardware is installed correctly and to load the basic input output system
• small in comparison to RAM
• programs may be stored in ROM embedded systems

Question 11

What happens when you shut down your computer?

Answer 11

Shutting down your computer is when all the software, programs, files, and processes are closed and the memory in the RAM is cleared. Before shutting down it is important to save all your work as your computer will not re-open anything you were previously working on before shutting down.

Question 12

What happens when you start your computer?

Answer 12

When you switch on a computer, a small program held in ROM called the bootstrap loader is automatically executed
The program performs some self-tests, and loads the operating system into memory

Question 13

Primary storage

Answer 13

The immediate memory the processor has access to.

• ROM
• RAM
• Cache and Registers

Question 14

Secondary Storage

Answer 14

Programs and data that are not in use by the processor are held on secondary storage media.

• Storage of programs and data when power is turned off
• semi-permanent storage of data that can change
• backup of files
• archive data files
• hard disk
• tape
• memory stick
• optical: CD/DVD

Question 15

Why is secondary storage needed?

Answer 15

Secondary storage is needed because the main memory in a computer system is usually either ROM which is read only and cannot be changed or the RAM which is volatile.

Question 16

Tertiary storage

Answer 16

Tertiary storage refers to the long term backup or archives stored. Backups are kept in case the main data file is lost or corrupt. Archives are data that is moved from the main files to free up space but still has to be kept for long periods of time

Question 17

Difference between hard disk and memory:

Answer 17

The hard disk, sometimes called the “hard drive” (which is actually the mechanism that holds the hard disk), is a spindle of magnetic discs that can hold several gigabytes of data. Memory, on the other hand, is not the same as disk space! Memory refers to the random access memory (RAM) inside your computer.

Question 18

Processor

Answer 18

A processor, or “microprocessor,” is a small chip that resides in computers and other electronic devices. Its basic job is to receive input and provide the appropriate output.

Question 19

The Cache

Answer 19

Very fast memory, inside the CPU. The bigger the cache, the faster the processor (usually measured in Mega Bytes MB),

Question 20

GPU

Answer 20

Most computers have a CPU and a separate graphics processing unit (GPU) for images. The GPU can be around 10 times faster than the CPU. It is optimised to produce high-quality 3D graphics for games and films. The GPU is responsible for handling images and frees up the CPU to do all other tasks.