Coincide with Spec Flashcards
What are the fundaments of a computer system
1) data is input
2) data is converted into an internal representation
3) the data is processed
4) the results of processing are converted from the systems internal representation to a user friendly out put by an output device
5) the data may be stored
6) the data may be used
7) the data may be transmitted to an additional computer while still holding the form of the computers internal representation
Define a computer system
A computer system is hardware and software working together to create a coded solution. It must be able to receive inputs process these and then produce an output
General purpose system
A general purpose system is usually found on laptops tablets and apart phones. A general purpose system is designed to perform a range of tasks and does not have one specific purpose.
Dedicated system
A dedicated system is a system used to perform single functions or a minuscule range of functions.
Embedded systems
Emmbeded systems are computer systems that are part of a larger system
Expert systems
Expert systems are systems that have a clear focus on a single task
Control systems
Control systems are systems that control machines , they are normally used in the manufacturing industry
Management systems
Management Systems collect data from several other smaller systems
What is the importance of computer systems in the modern world ?
1) they allow us to contact and work with people regardless of location
2) they mean data can be accessed securely from a range of locations
3) they improve quality of life , those without limbs can have them replaced by bionics
4) they save time thus services such as that of the fire , police and ambulance can coordinate responses quickly and swiftly implement resources using computer systems
What is the reliability of a computer system
The reliability of a computer system is how dependable it is to do the job you entrust it with.
Computer systems need to be reliable as technology is not worth possessing if it does not function correctly or puts your previous work at risk
Factors which can affect the reliability of a computer system include
- human error
- virus
- hardware malfunction
Professional standards
It is important that manufacturers of computer systems implement professional standards to ensure there is an element of quality control . It is the responsibility of the manufacturer to make the computer system safe for the consumer . The system must work within range of a suitable efficiency and hence must function correctly which can be ensured by obliging by professional standards
Ethics
When developing a computer system ethics must be considered hence the privacy of a user becomes a pressing question , can governments access user data , can peers access user data or is the data maintained as confidential . There also must be user access levels to ensure no sensitive information can be accessed by unauthorised personal which would be an ethical injustice in the case of computer stores of medical records and such alike
Environment
Computer systems must oblige by government energy regulations which consequently means they must coincide with a set standard of efficiency
Laws
Legal issues must be considered this a system must not violate laws such as those of copy right
what does CPU stand for
Central Processing Unit
What is the purpose of the CPU
The CPU is a piece of HARDWARE within a computer system whose purpose is to process data
What is the function of the CPU
Fetch - The CPU searches and retrieves instructions from the computers memory
Decode - the CPU breaks down the problem to enemies the computer can gain an understanding of the task
Execute - the CPU runs a task meaning the instruction the is ‘fetched’ is carried out
What is the importance of the CPU
1) the CPU connects items in a computer system together such as the memory and output devices
2) it is the central processor hence it has the capacity to dictate the response of a system based on an input
3) it can carry out several tasks within a period of time as it processes them sometimes simultaneously
How does the Number of cores affect the performance of the CPU
A CPU can have multiple cores , these allow for multiple instructions to be executed simultaneously . If a program is optimised to use more cores it will mean the program will run faster
What is the measurement of processor speed ?
Giga hertz (GHz)
How does the clock speed affect the performance of the CPU
The CPU needs to complete a certain number of ‘cycles’ to execute each task . The clock speed is the amount of cycles that can be executed in one second , the faster Jesé cycles complete the more tasks can be carried out per second . Increased clock speed in the CPU means increased performance of the computer system . Clock speed is measured in the same way as processor speed - in giga hertz (GHz)
How does the size of the cache memory affect the performance of the CPU
Cache is the type of memory that stores frequently accessed instructions so that they can be quickly fetched and executed when requested by the user . If the CPU has more cache memory it will have a better performance as more data will have a quicker retrieval time.
How would you explain our number system
Our number system is that which we call base 10 it has 10 digits
We refer to this number system as deanery
Explain binary
Binary is a base two system as it only uses two digits
0 and 1
In a computer system everything is represented by binary digits as they symbolise a voltage 1 being on while 0 is off
Boolean logic / logic gates
NOT gate
In a not gate the input is reversed as the gate is an inverter
Input. Output
- 0
- 1
Boolean logic / logic gates
AND gate
The gate revives two inputs and produces a single output , both inputs must be true in order for the out put to be be true
a AND b must switched on in order for a positive output to prevail
Input A. Input B. Output
1. 1. 1 0. 0. 0 0. 1. 0 1. 0. 0
Boolean logic / logic gates
OR gate
The gate revives two inputs and produces a single output , at least one of the inputs must be true in order for the out put to be be true
a OR b OR both must switched on in order for a positive output to prevail
Input A. Input B. Output
1. 1. 1 0. 0. 0 0. 1. 1 1. 0. 1
RAM
RAM = random access memory
- it’s a form of memory which can be accessed quickly
- it is volatile memory , every thing is lost if the device looses power
- it’s purpose is to store all the data associated with programs that are currently open
- it is a form of temporary storage
- if a computer has more ram it will run more quickly
- large capacity
- can be accessed and changed by the computer
- more RAM means better performance
ROM
ROM - Read Only Memory
- a form of storage that contains pre recorded data
- data in the ROM cannot be edited only read
- ROM is non volatile all data is retained even when the device looses power
- small capacity
- programmed during the manufacturing of the device
- the ROM contains essential programs such as Ines which allow the computer to start up
Virtual memory
Virtual memory is used when all of the RAM has been used up . It is an extension of the RAM
Data that has been held in the RAM that has not been opened in a while may move into the virtual memory. Data in the virtual memory can be accessed far more slowly than data in the RAM . Having a larger RAM means less is stored in the virtual memory this is a benefit as fetching from the virtual memory takes a lot longer
Cache Memory
Data that is frequently used is stored in the cache memory this means future requests can be served more quickly however it is a very expensive type of memory
Flash memory / solid state memory
Flash memory is a type of non volition memory that uses solid state technology . Flash memory has no moving parts this means the form of memory is more durable . The benefit to this type of memory is it can be accessed quickly and also can transfers data between devices as it can be easily moved around (memory sticks)
Advances in memory technology
As memory technology advances data retrieval is becoming much faster . The storage capacity of devices are increasing while the actual size of the storage device is getting smaller this means a computer can store more without increasing its size . It also means because of the reduced size Meier can be transferred between devices as it can be physically moved . Increased memory capacity increases the performance of a computer
Input devices
An input device enters data for processing it may include
- keyboard
- mouse
- scanner
- microphone
- light sensor
Output devices
An output device is something that delivers an output after the processing of an input
Some out put devices may include :
- printer
- speaker
- Monitor (non interactive touch)
- heater
Devices for people with specific needs
Brail keyboard (input) - to help users that are blind or visually impaired to type
Voice recognition (input) those who are physically incapable of using physical inputs can control the computer via the use of their voice
Brail printer (output) users whom are blind or visually impaired are this capable of reading the output of the computer system
Computational narration (output ) those whom have visual impairments are able to understand the display of the computer and Coke to know the results of the execution of the task
Secondary storage
Secondary storage is a physical attrition to the computer system it is not internal but rather added to the system
Secondary storage is important as it is able to retain the data stored in the RAM when the device looses power . Secondary storage is non volotile
Optical storage
Optical storage devices store data in patterns of dots that are burnt in to the disk usually using a powerful laser
These dots can be read through bouncing a laser beam over the surface of the medium . If the beam hits a dot the light is refracted back differently this difference can be detected thus the data can be read. Types of optical storage include
- CDs
- DVDs
- Blue-ray disks
Solid state storage
Solid state storage is essentially a type of storage that has no moving parts , they are formed using large electrical circuits . Solid state memory is fast , reliable and portable . It can be found in devices such as
- USB memory sticks
- memory cards
- SD cards in cameras
- SIM card in phones
Magnetic storage
Magnetic storage holds data in the form of tiny magnetised dots , these can be read using magnetic field s which are created using tiny electro magnets . Magnetic storage normally had a large capacity . It can be found in devices such as
- hard drives
- Magnetic tapes
- Floppy disks
When choosing a type of storage the following considerations should be made
Capacity - how much data can be stored
Speed - how quickly can data be read as written
Portability - how easy is it to travel with / can it be removed
Durability - how easily damaged is it
Reliability - how likely is it to malfunction
What is hardware
Hardware is the physical parts that make up the computer system
What is software
Software is the range of programs used to control the computer system
What is an operating system
An operating system is the essential peice of software that links hardware and other software applications together, some common operating systems include
- Android
- iOS
- windows
