computer systems

Question 1

what is hardware?

Answer 1

anything that physically makes up the computer

Question 2

what is software?

Answer 2

any program or operating information that runs on or is used by the computer

Question 3

what is the notation for the NOT gate?

Answer 3

an overbar

—–

Question 4

what is the notation for the AND gate?

Answer 4

a dot above .

Question 5

what is the notation for the OR gate?

Answer 5

a plus +

Question 6

what is the notation for the XOR gate?

Answer 6

⊕

Question 7

write a truth table for an AND gate with two inputs

Answer 7

0 0 - 0
0 1 - 0
1 0 - 0
1 1 - 1

Question 8

write a truth table for an OR gate with two inputs?

Answer 8

0 0 - 0
0 1 - 1
1 0 - 1
1 1 - 1

Question 9

write a truth table for an XOR gate with two inputs

Answer 9

0 0 - 0
0 1 - 0
1 0 - 0
1 1 - 1

Question 10

write a truth table for an OR gate with two inputs?

Answer 10

0 0 - 0
0 1 - 1
1 0 - 1
1 1 - 1

Question 11

write a truth table for an NOT gate with one input?

Answer 11

0 - 1

1 - 0

Question 12

what is system software and some examples?

Answer 12

programs needed for the computer to function

• utilities
• operating system
• library routines
• programming language translators

Question 13

what is application software and some examples?

Answer 13

programs that enable a user to do a task

• games
• a spreadsheet
• word processor
• web browser

Question 14

what five things does the os manage?

Answer 14

• processor
• memory
• input / output devices
• applications
• security

Question 15

what are some advantages of high-level languages?

Answer 15

easier to read

easier to learn

Question 16

what does the os do, regarding memory?

Answer 16

• manages the computer’s memory

- it can control which parts of the memory are being used for each process

Question 17

what does the os do, regarding processing?

Answer 17

• manages the computer’s processor(s)CPU;

- Schedules which processes are to be executed;

Question 18

what does the os do, regarding applications?

Answer 18

Control access to applications;
- Prevent users or processes using unauthorised programs // allow users or
processes to use authorised programs;
- Control application access;
- Prevent/allow an application access to data (or devices);

Question 19

what does the os do, regarding security?

Answer 19

User authentication;
- To make sure that users must prove who they are to access the system;
- Protect against malware;
- Block access to specific vulnerable operations or system areas. For
example, software can only be installed with admin access;

Question 20

what does the os do, regarding input /output devices?

Answer 20

• manages input/output devices
• Interacts with/manages/handles the (automatic) installation of device
  drivers;
• Handles peripheral device interrupts;
• the computer can communicate with the outside world;
• Control network communication;
• Allow devices to send and receive data;

Question 21

what is primary storage?

Answer 21

the memory areas that the CPU can access directly: registers, cache, ROM and RAM

Question 22

what is secondary storage?

Answer 22

isn’t directly accessible by the cpu ( where all data is stored that is not in use

Question 23

what is the volatility and speed of primary storage compared to secondary storage?

Answer 23

primary is mostly volatile ( needs power to be stored ( will delete when the device is turned off )
and also faster to read and write

Question 24

advantages of magnetic hards disks

Answer 24

high-capacity
reliable
cheap

Question 25

why is secondary storage required?

Answer 25

for long term non - volatile storage
to store data
and to transfer data to another device

Question 26

advantages of solid state drives

Answer 26

fast read and write speeds
reliable
lower power usage
light

Question 27

advantages of optical discs

Answer 27

cheap
portable / easy to transport
robust

Question 28

disadvantages of magnetic hard disks

Answer 28

not very portable
can be corrupted by a magnetic field
can break easily

Question 29

disadvantages of solid state drives

Answer 29

expensive
slightly lower capacity than hdds
begin to deteriorate / shorter read and write life

Question 30

disadvantages of optical discs

Answer 30

easily scratched
low capacity
very slow read and write speeds