Hardware and software - video 104 - 107

Question 1

what does paradigm mean in a computing context

Answer 1

to describe an example of a way of doing things

Question 2

what languages are programs grouped into

Answer 2

-low level languages
- high level languages

Question 3

summarise machine language

Answer 3

• accesses the hardware directly
• works with binary numbers representing different instructions
• the instructions as well as the addresses in memory where data was being stored also had to be referred to as nimbers

Question 4

summarise assembly language

Answer 4

• each opcode was replaced by a mnemonic which gave a clue to what the operator was doing
• the operand was replaced by a decimal or hexadecimal number
• one to one relationship

Question 5

advantages of assembly language

Answer 5

made programming more accessible
- executes code as fast as possible
- occupies little space
- can manipulate individual bits and bytes
- used in stuff like interrupt handlers and time systems

Question 6

why are machine language and assembly language called low level languages

Answer 6

because they are very close to the actual hardware

Question 7

What are high-level programming languages?

Answer 7

Languages where each instruction could give rise to many lines of machine code

Question 8

example of high level languages

Answer 8

• FORTRAN
• PYTHOM
• C#

Question 9

what is imperative language

Answer 9

when program code is executed one line at a time, written using sequence, selection, iteration and subroutines/procedures

Question 10

advantages of low level language

Answer 10

• not all low level languages need to be translated, all high level languages do
• low level languages program are likely to use less memory when executing
• low level languages programs may execute faster than HLL
• low level language programs can directly interact interact with hardware

Question 11

disadvantages of machine/assembly language

Answer 11

• machine dependent, code produced is very hard to port
• finding programmers that are capable of writing efficiently in assembler is hard
• it can be long and tedious to write
• is very bug prone
• the code can be difficult to understand, making it hard to modify and maintain

Question 12

things that will affect processor performance

Answer 12

• clock speed - increasing clock speed increases the number of instructions executed per unit time
• word length - increasing word length means the processor can handle more data per instruction
• bus width (adress or data)- increasing the address bus size means we can address more unique memory locations
• the number of cores linked together on a single chip
• the amount and type of cache memory

Question 13

what are the roles of the address hus, data bus and main memory in the fetch part of the cycle

Answer 13

• Adress in the MAR is sent down address bus to main memory
• contents of address location sent down the data bus

Question 14

why can the fetch steps occur at the same time

Answer 14

because one step does not rely on the prior completion of the other

Question 15

when might the status register have a bit set

Answer 15

when there is an interrupt
- when there is an illegal instruction
- overflow or underflow

Question 16

what is assembly language formally known as

Answer 16

second generation

Question 17

imperative high level languages

Answer 17

• each instruction is basically a command to perform some step in the program

Question 18

what are high level languages

Answer 18

languages that enable programmers to think and code in terms of algorithms

Question 19

advantages of high level languages

Answer 19

• relatively easy to learn / interpret
• easier and faster to write a program in HLL
• programs written in HLL are easier to debug, maintain and understand
• programs written in HLL are machine independent, they can be run of different types of hardware
• there are many built in library functions available in most HLL
• different HLLs are usually written specifically for a particular class of problem
• HLL languages may have a wider range of programming structures like loops available

Question 20

types of system software and their uses

Answer 20

• translators - convert code into machine code
• utility software - programs that help optimize the computer, eg virus scanners and disk drfragmenters
• operating systems - manage all operations of the hardware, they provide a user interface
• libraries - pre written pre tested code used to develop software

Question 21

what is software

Answer 21

programs which run on the computer

Question 22

general purpose software

Answer 22

software that can carry out many tasks

Question 23

why might someone pick a special application software over bespoke

Answer 23

• most likely to be bug free as it has already been tester
• lower costs and development costs are shared

Question 24

differences between interepreter and compilers

Answer 24

Execution Process:
Compiler: Converts the entire source code into machine code before execution, producing an executable file.
Interpreter: Translates and executes source code line by line, without generating an intermediate executable file.
Speed:
Compiler: Generally produces faster execution as the entire program is translated into machine code beforehand.
Interpreter: May result in slower execution since the source code is translated into machine code line by line
Compiler: Performs a thorough analysis of the entire source code before execution, detecting errors during compilation.
Interpreter: Detects errors as it executes the source code line by line, stopping execution when an error is encountered.

Question 25

advantages and uses of LLLs

Answer 25

• closer to executable machine code than HLLs
• easier for the computer to understand
• they provide exact control over the CPU
• they need less translation and lead to faster code
• useful for computers with low specifications such as embedded systems

Question 26

what are declarative languages and examples

Answer 26

• languages that define what is to be computed
• SQL is an example

Question 27

why do we use LLS

Answer 27

• higher execution speed
• minimal object code size
• directly access the hardware

Question 28

what is imperative language

Answer 28

• when the programmer gives the computer a sequence of instructions to perform

Question 29

features of imperative language

Answer 29

• includes libraries
• uses compilers
• a compiler may not be available for a specific processor