Topic 6 - Computer systems - Complete

Question 1

Define software?

Answer 1

Refers to the program or coded instructions that make the computer run,

Question 2

Define hardware?

Answer 2

Refers to the physical part that makes up a computer system.

Question 3

Define system software?

Answer 3

Is needed to carry out the tasks to operate the hardware.

Question 4

Define application software?

Answer 4

Is needed to help carry out user-related tasks, such as Word processing, Payroll & air traffic control.

Question 5

What are the 4 features of system software?
O
L
U
P

Answer 5

• Operating system
• Library programs
• Utility programs
• Programming language translators

Question 6

What are the 3 types of application software?
G
S
B

Answer 6

• General-purpose (GP)
• Specialised applications (SA)
• Bespoke applications (BA)

Question 7

What are some features of the operating system (OS)?

Answer 7

Controls the hardware and hides the complexity of the hardware by creating a platform to run application software.

Question 8

What are some features of library programs?

Answer 8

Are pre-written software that is stored in compiled format and can be included by the programmer within one or more programs.

Question 9

What are some features of Utility programs?

Answer 9

Are a range of system software that is designed to help the user to manage, maintain and optimise the system.

Disk formatting, file compression, data synchronisation, firewall, memory testing and anti-virus protection.

Question 10

What are some features of programming language translators?

Answer 10

Used to translate a program in one programming language into a different programming language and to maintain the functionality of the original code.

Question 11

Define these 3 types of translators?
Assembler
Compiler
Interpreter

Answer 11

Assembler - Used for assembly language programs
Compiler - Used for program languages like C++, Visual
Interpreter – Used for program languages like python

Question 12

Define machine code?

Answer 12

Is the set of binary instructions that are used by the CPU to perform a task. Is processor dependant.

Question 13

Define assembly language?

Answer 13

Is a low-level programming language which is processor-dependant, each instruction is one machine code operation.

Question 14

Define high-level languages?

Answer 14

Is a computer programming language based on natural language or mathematical notation.

C++, Python, Java

Question 15

Define declarative?

Answer 15

high-level languages are also based on natural language and are used to declare the necessary information to produce the required result.

Question 16

Define imperative language?

Answer 16

Program statements or instructions are executed in a sequence or order as defined by the programmer. High-level languages are imperative.

Question 17

Define the advantages of low-level language (machine code & assembly language) compared to high-level language?

Answer 17

Programming in low-level code can create faster and more efficient code as the programmer controls the performance level of the created code. More memory efficient.

Question 18

What are the advantages of high-level languages?

Answer 18

It is difficult to learn to program in low-level languages whereas high-level languages have more support and training options. Easier to debug.

Question 19

Define source code?

Answer 19

Is the language instructions that have been written by the computer programmer. The computer cannot execute the source code directly.

Question 20

Define object code?

Answer 20

Is translated from the source code using an assembler or compiler into instructions that can be executed by the compiler.

Question 21

Define assemblers?

Answer 21

Series of memorable mnemonics used to represent machine operational code. Assembly code is the most difficult language to program and needs a high degree of expertise to write and debug it.

Question 22

What are the pros and cons of assemblers?

Answer 22

Pros: An efficient low-level language that can be translated quickly as it has a one-to-one relationship with machine code.

Cons: It is complex to write and takes lots of programming time and expensive

Question 23

Define compilers?

Answer 23

The compiler converts the source code to an object, which the computer can run. Source code created by the programmer is not understandable by the computer.

Question 24

What are the pros and cons of compilers?

Answer 24

Pros: An executable file is produced which runs without the need of the source code. This makes the source code more secure as it does not need to be distributed to the customer.

Cons: Complication of a large program takes a long time to complete and any errors in the source code need to be corrected before an executable file can be made.

Question 25

Define intermediate language?

Answer 25

Some compilers create a final output in an intermediate language such as bytecode. The output is designed to run on a virtual machine rather than on a central processing unit.

Question 26

Define Interpreters?

Answer 26

Interpreter software normally executes the source code directly, it is translated line by line, this avoids the need to compile the program.

Question 27

Define a logic gate?

Answer 27

Are circuits that are used to perform a logical operation in computing and electronics

Question 28

Define a truth table?

Answer 28

Is a diagram that shows all possible logical inputs and their associated outputs.

Question 29

What are the 3 main logic gates?

Answer 29

NOT
AND
OR

Question 30

What are the 3 other logic gates?

Answer 30

XOR
NAND
NOR

Question 31

Define the NOT gate?

Answer 31

The output is opposite the input

One input & output

Question 32

Define the AND gate?

Answer 32

Two or more inputs where the output is true if all the inputs are true

Question 33

Define the Or gate?

Answer 33

Two or more inputs where the output is true if either or both inputs are true.

Question 34

Define the XOR gate?

Answer 34

Two or more inputs where the output is true ONLY if one input is exclusively true

Question 35

Define the NAND gate?

Answer 35

Two or more inputs where the output is false when all inputs are true

Question 36

Define the NOR gate?

Answer 36

Two or more inputs where the output is true when all inputs are false

Question 37

Define half adder logic?

Answer 37

Hald adder circuits carries out addition on two numbers (A and B) only.

Sum - A XOR B
Carry - A AND B

Question 38

Define full adder logic?

Answer 38

Full adder circuits carries out addition on two numbers (A and B) and a carry bit.

A series of full adders can be used to add binary numbers, as the carry bit is available at each stage of the calculation.

Question 39

Define a flip flop?

Answer 39

Is an electronic circuit that has two stable states and can be used as a memory device to store one bit of data

Question 40

Define a D-type flip flop?

Answer 40

Changes the state with each clock pulse, so data is delayed by one clock pulse

Question 41

Define Boolean expressions?

Answer 41

Are used in computer programs, when these expressions are evaluated they give a boolean logic output of either True or False.

Question 42

What does each symbol mean?
+
.
Ā

Answer 42

+ Or
. AND
Ā NOT

Question 43

State the 8 AND logic identities?
1.A
0.A
A.A
A.Ā
A.B
A.(B.C)
A+(B.C)
A.(A+B)

Answer 43

1.A=A
0.A=0
A.A=A
A.Ā=0
A.B=B.A
A.(B.C)=(A.B).C
A+(B.C)=(A.B).(A+C)
A.(A+B)=A

Question 44

State the 8 OR logic identities?
0+A
1+A
A+A
A+Ā
A+B
A+(B+C)
A.(B+C)
A+(A.B)

Answer 44

0+A=A
1+A=1
A+A=A
A+Ā=1
A+B=B+A
A+(B+C)=(A+B)+.C
A.(B+C)=(A.B)+(A.C)
A+(A.B)=A

Question 45

Define Dr Morgan’s Law?

Answer 45

Change all AND operators to OR
Change all OR operators to AND
Change the logical state of each variable