Computer Systems

Question 1

What is hardware?

Answer 1

Tangible physical components of a computer system.

You can feel it or touch it.

Question 2

Examples of hardware

Answer 2

Monitor, printer, mouse, keyboard, CPU

Question 3

What is software?

Answer 3

Programs that control computer systems.
Set of instructions that make the computer system do something.
You cannot physically touch software.
Relates to ideas and instructions for using physical objects.

Question 4

Examples of software

Answer 4

Two main types: Systems Software
Programs that allow the hardware to run properly.
Control computer’s hardware and application program.
Communicate with user.
E.g. Operating system.

Application Software:
Programs that allow the user to do a specific task.
Can be general purpose software or custom made software (specialist software).
E.g. Spread sheets, databases, word processing.

Question 5

The basic computer system model

Answer 5

Input
    |
Process ----- Storage
    |
Output

Question 6

What makes up the CPU

Answer 6

Three main components:
Control unit - coordinates input and output devices and carries out program instructions.
Arithmetic and Logical Unit (ALU) - performs calculations and logical comparison: A < B?.
Immediate access store (IAS) - holds data and program instruction in current use.

Question 7

What is RAM?

Answer 7

Random access memory (RAM) is an internal chip where data is stored temporarily.
Memory can be written to and read from
RAM stores program instructions and data that are needed when a program is running.
Contents are lost when computer is turned off.
Referred to as volatile memory.

Question 8

What is ROM?

Answer 8

Read only memory (ROM) is memory used to store permanent information.
Used to contain configuration data for a computer etc.
Chips cannot be altered, only read from.
Data not lost when computer is turned off.
Referred to as non-volatile memory.

Question 9

What does the Operating System do?

Answer 9

Enables users to communicate with computer systems.
Controls operation of input, output and backing storage device.
Supervises loading, running and storage of application program.
Maintains security of whole computer system.
Main types of user interfaces: Command Line Interfaces (CLI) and Graphical User Interface (GUI).

Question 10

Advantages of GUIs

Answer 10

Easy to use.
Easy to explore and find your way around the system.
Do not have to learn complicated commands.
Good help facilities provided with GUIs.

Question 11

Disadvantages of GUIs

Answer 11

Larger amount of hard disk space than other interfaces.
Significantly more memory (RAM) to run than other interface type.
GUI use more processing power than other types of interfaces.
GUI can be slow for experienced programmers to use.

Question 12

Advantages of CLIs

Answer 12

Uses much less memory (RAM) than any other interface type.
Low resolution, cheap monitors can be used.
CLI does not require Windows to run.
Faster for expert users.

Question 13

Disadvantages of CLIs

Answer 13

Can be confusing.
Commands have to be typed precisely, if there is a spelling error the command will fail.
Large number of commands need to be learned.

Question 14

Different types of Computers

Answer 14

PC/Desktop Computers
Laptop (Notebook)
Netbooks
Personal Digital Assistants (PDA)
Tablets
Main frame computers

Question 15

Advantages/Disadvantages of Laptops

Answer 15

Ads: Portable
No wires
Low power consumption
Disads:
Easy to steal
Limited battery; need to carry charger
Keyboard and pointing device awkward to use

Question 16

Advantages/Disadvantages of PCs

Answer 16

Ads:
Spare parts standardised results in low costs
Tend to have better specifications
Large casing allows good dissipation of heat build up
Disads:
Not portable since they are not made up of separate components
Wiring clutters up desk space
Necessary to copy files as they aren’t portable