3.6 Fundamentals of computer systems

Question 1

hardware definition

Answer 1

physical components of the computer system, internal and external

Question 2

software definition

Answer 2

sequences of instructions which are executed in order to perform a task

Question 3

application software

Answer 3

performs user-oriented tasks such as word processors

Question 4

system software

Answer 4

management of computer system, includes utility, library programs and translators

Question 5

operating system

Answer 5

allows user to control computer with ease as it provides user with a virtual machine (hiding true complexity of the computer from the user), resource management

Question 6

resource management OS

Answer 6

memory management, processor scheduling, handling interrupts

Question 7

utility programs

Answer 7

performs tasks that help manage a computer, examples: data backup, encryption

Question 8

library programs

Answer 8

contain frequently used functions, simplifies process of making program

Question 9

translators

Answer 9

translate between different types of language, three types include compilers, assemblers, interpreters

Question 10

low level languages

Answer 10

machine code and assembly language

Question 11

machine code

Answer 11

uses binary digits to represent instructions, no need to translate, useful for real-time applications due to its speed of execution

Question 12

assembly language

Answer 12

uses mnemonics so its more compact and less error prone

Question 13

high level languages

Answer 13

not platform specific, needs to be translated before executing, built-in functions, includes imperative high-level languages formed from instructions that specify how a computer should complete a task

Question 14

portability of low vs high level languages

Answer 14

low level: machine code - not portable, assembly language - processor specific,
high level: portable, programs not specific to certain processors

Question 15

ease of use of low vs high level languages

Answer 15

low level: machine code - difficult to understand, assembly language - mnemonics so slightly easier,
high level: uses english so it is easy

Question 16

ease of debugging of low vs high level languages

Answer 16

low level: machine code - errors are very difficult to spot and correct,
assembly language - easier than machine code,
high level: named variables and indentation and commenting make debugging easy

Question 17

ease of execution of low vs high level languages

Answer 17

low level: machine code - directly executed,
assembly language - assembler must be used before program is executed but quick translation,
high level: compiler or interpreter must be used to translate source code into object code before execution

Question 18

assembler

Answer 18

translates assembly language into machine code, each instruction has 1-1 relationship to machine code so translation is quick, platform specific

Question 19

compilers

Answer 19

translates high-level language into machine code,
takes program as source code and checks for errors before translating entire program at once,
any error in source code and it will not be translated, platform specific,
once translated it does not need any other software

Question 20

interpreter

Answer 20

translates high level language into machine code line by line, checks for errors as it goes, program can be partially translated until the error is reached, source code and interpreter must be present for execution

Question 21

compiler vs interpreter

Answer 21

comp: checks source code line for errors line by line, entire source code translated at once, no need for source code or compiler to be present for execution, protects source code from extraction,
inter: translation begins immediately, each line is checked and translated sequentially, both source code and interpreter must be present for execution, offers little protection of source code

Question 22

compilers with intermediate languages

Answer 22

compilers can code into an intermediate language instead of machine code, allowing for platform independence, intermediate language can be used with a virtual machine to execute bytecode on different processors, allows interpreter to translate source code once

Question 23

source code definition

Answer 23

input to a translator (assembly language for assembler, high level language for compilers and interpreters)

Question 24

object code

Answer 24

output of translator, produced from source code

Question 25

half adder definitions S and C

Answer 25

adds two boolean values, S = A XOR B, C = A AND B

Question 26

full adder

Answer 26

three inputs and two outputs allowing it to input two values and a carry bit

Question 27

edge triggered D-type flip flop usage

Answer 27

logic circuit that can be used as a memory unit for storing the value of a single bit

Question 28

D-type flip-flop inputs

Answer 28

data input and clock signal

Question 29

D-type flip-flop output

Answer 29

output holds the value of the stored bit

Question 30

D-type flip-flop clock signal

Answer 30

value of stored bit is set to the value of the data input with each change of the clock signal, can also synchronise multiple flip-flops