Computer Fundamentals and Information Processing Flashcards
What is a computer
An electronic device operating under the control of instructions stored in its memory that can store data, manipulate data, produce results and store data for further use.
Name of computer memory
Ram or Main memeory
Mother board layout
CPU, RAM and connection to hardrive
Computer follow the four basic task of the IPOS cycle
Input, Processing, Output, Storage
The types of computer components
Hardware and software
What is hardware
any physical part of the computer
Types of hardware
CPU- Control processing unit is the brain of the computer that controls the rest of the computer and has two parts
*the CU Control unit (this carries out instructions in the software and directs flow of data in computer)
*The ALC Arithmetric and logic unit (this performs calculations and logic operations)
Input devices get data into the computer
Output devices get process information out the computer
Memory enables a computer to temporarily store instructions and data
Storage media includes CD-ROMS and DVS and UBS flash memory sticks (what is storing the data the physical media)
Storage devices include hard disk drives, CD-ROM drives and DVD drives (ends with the word drive and facilitate the transfer of data)
Peripheral device are located outside the CPU and controlled by it
What are computer programs
These are instructions produced by programmers to create system and application software
Software
This the instructions that tell the computer what to do
System software
This software is called operation software because it controls the hardware and how other software works. Microsoft Windows 10, Apple IOS, Linux is an example
What is utilitiy software
This aims to protect and maintain the system software.
Examples protecting software against virus and making copies of files and recovering files after software crashed
Examples: Norton, mcafee, AVG, Google drive, Icloud
Application Software
This is the software that instructs a computer to carry out a specific task. Example spread sheets, Word (Not needed for computer to run)
What is IT? (ARCSOMP)
This is the term to describe the equipment that allow us to access, retrieve, convert, store, organise, manipulate and present data and information
Communication (CT)
This is the term used to describe telecommunications equipment through which data and information can be accessed.
Examples of CT= Phones, Faxes, Scanners, modems and computers
Types of data devices
Manual and direct data devices
Manual data
you enter data into computer yourself
Example of manual devices
Digitiser convert drawings and imagines into data example digital camera and webcam.
Keyboard
Keypad
Special Keyboard- any devices that has buttons on it designed to just one job
Mouse(ball) and optical mouse (laser)
Document scanner- allows you to transfer pictures and graphic and text to ur computer
Microphone
Touch screen
Touchpad
Pointing device
Remote control devices
Lightpen
Stylus
Bio-metric systems
Direct data entry
information is transferred automatically from a document
Examples of DDE
Barcode reader (this is used with electronic point of sales system (EPOS))
Smart card
Magnetic swipe card (black strip)
Optical mark recogonitition (OMR) These transer marks into the system
Optical character recogition (OCR) Enters hand written or printed text into the computer system
OMR and OCR are used together in a turn around document, this type of document one side has unique information on one side and the other side has information needed to be added by a human
Magnetic ink character recognition (MICR)- This is used to process cheque number, account number and branch code printed on the cheque with magnetic ink
Types of Sensors MIDI musical instrument digital interface
Types of output
Soft copy output- What we cannot touch or feel and not permanent. Examples computer monitor, audio speaker
Hard copy output- This is permanent output since it is printed. Examples printed reports and pictures
Display devices
Display devices- anything that displays output on a screen example smartboards and computer
Types of display devices are liquid crystal display (LCD) and light emitting didode(LED)
Features of computer screen
Size-Measured diagonally
Resoloution- pixels per inch determine how clear and detailed the output
Colour- number of colours that can be displayed , more colour smoother the display
Cursor/pointer- symbol to show where u are working on the screen
Scrolling allows the text or grahpic to me moved up or
down on the screen
Priniting devices
Impact printer- hitting page like type writer, they uses carbon paper, used for printing payroll and financial reports need continuous sheets of paper
Example: Dot-matrix printer- very loud and uses pins to print a pattern of dots on paper,
advantage used for multiple copies
disadvantage can be read but not used for reproduction or business letters
Non impact printer- does not touch the page, ink is sprayed or toner powered is used, the characters are fixed onto pages by heating
Example: Ink jet printers they are low priced good quality printer that print in black and white or colour by spraying ink on page
Laser printer- this uses toner powder, high resolution and faster than ink printers they are quiet, stocked with multiple sheet
Thermal printer: this uses heat, used in Automatic banking machine (ABMS) receipts, debit and credit card slips and even ultrasound scanned images uses this printer. They are quiet and recent ones print quickly however paper is expensive and the print fades if exposed to light or heat
3D Printer- has layers from bottom upwards and the model is created in hours and melted plastic that sticks to each new layer
Plotter- used by car designer, architects and engineers who wish to print accurate charts, diagrams and 3D drawings. Colour pens or toner is used to draw image on paper.
Three types of plotter- Flatbed, Drum (bigger diagram) and Pinch-Roller (mixture of 2)
Primary memory
Primary memory is computer memory that a processor or computer accesses first or directly
Main memory or RAM is located directly on computer’s main circuit board so data can travel quickly to and from the CPU
Data stored a specific memory location is called an address, can have its address contents accessed to read from or written to or processed.
Word is the largest amount of data that can be moved together to be processed
Types of memory
RAM- Random access memory,computer access data held in RAM almost immediately, data is lost when u lose power(RAM is volatile)
ROM- Read only memory- the basic input/output instructions put in a computer when the computer is made, these instructions are read but cannot be changed (Non-volatile)
Hybrid memory/ Flash memory- U can both read and write the data
How data is represented
The computer sees in binary, 1= on and 0=off
Storage Unit
Unit Abbreviation Storage
Bit B single 1 or 0
Nibble 4 bits
Byte/Octet B 8 bits
Kilobyte KB 1024 bytes
Megabyte MB 1024 KB
Gigabyte GB 1024 MB
Terabyte TB 1024 GB
Petabyte PB 1024 TB
Secondary Storage
Secondary storage refers to the media and methods used to keep programs, data, and information available for later use
Examples
Secondary storage media and storage devices
Secondary storage media keep data, instructions and information on physical hardware of a computer for future use examples Hard disks, compact disks ad tapes
Storage devices record and retrieve data instructions, and information to and from storage media. Example hard disk drives and tape drives
Types of storage
Local storage involves users having storage devices or media with data in their possession
Local storage-
*Magnetic media such as magnetic tape and hard disk
*Optical disks such as CD-ROM, CD-R AND DVD
*Flash memory
Cloud storage
Magnetic Media
This is the cheapest way to store and back up data
Magnetic tape- Backing up media but slow store a large amount of data for long, stores data sequentially not random access
Hard disk-
Optical disk
CD- ROM
CD- R (Recordable)
CD-RW
DVD- Digital versatile disk
Blue- ray
Flash memory
Combines best features of memory devices. Store large amounts of data, are low cost, non-volatile. fast(to read not to write) and electrically re-programmable
Flash memory cards
Cloud based storage
storage of data by users on multiple computers anywhere in the world
Examples Dropbox, Google drive
Booting
How the computer starts up,
1.bio chip (ROM) starts up that checks the entire system, one beep means everything ok
2.Looks for operating systems and loads operating onto RAM
3.The data goes back from RAM to CPU
Hardware Control
The operating system controls all the data in your hardware
Software contol
The operating system controls how all the software applications, games and other programs work
Memory management
virtual memory is an extension of the ram, when the ram full the operating system delegates some of the data into the hard drive
Input Output management
The flow of information among devices must be managed and coordinated
Process management
Time for processes to use the CPU, checks on processed waiting to use the CPU and signals when the CPU is available
File managent
Operating system checks amount of memory need to perform the task of files needed to be saved copied renamed and deleted and manages the organisation of the files in secondary storage
Types of operating system processing
Batch processing- system in which data is collected together in a batch before processing starts, it is used when large amount of data is processed on a regular basis
Example: utility bills
Advantage once data is is submitted for batch processing the computer can be left running without human interaction
Jobs can be scheduled for a time when the computer is not busy
Disadvantage
There is always a delay before work is processed and returned since batch jobs are usually stored up over time
Time-sharing allows many users to share time on a single computer. Each user is given a slice of CPU time by the computer
Other types of operating system control
Multitasking- allowing more than one program to run at the same time
Multiprocessing- executing programs using 2 or more processors simultaneously
Multi-programming: executing 2 or more programs at the same time with only one processor
MULTI-USER: ALLOWING MORE THAT ONE USER ON A COMPUTER NETWORK TO ACCESS THE SAME FILE
Online and real time processing
The device is on and is processing data
Real time processed data without delay making it up to date
The difference is online means the device is on but real time means the device accept the data right away and give out the data right away
Advantages: No significant delay
Information up to date
Dis advantage: system have to be dedicated to the task
The computer must be online
Real time is online but online doesn’t mean real time example forecast
What is uploading
tranfer data from ur device to another device
Downloading
when u recieve
File transfer protocol (FTP)
a network protocol for transmitting files between computers
File compression
reducing the size of a file or combining files
The bigger the file the longer it take to transfer
File types
Graphics- JPEG (JOINT PHOTOGRAPHIC EXPERT GROUP)
PNG (Portable Network Graphic)
Music- (MP3)
Video- (MP4)
Types of application software
General purpose software- not for a specific organisation and can be used by anybody like spreadsheets
Customised software- general purpose software that has been modified to perform specific task for the user
Custom written software also know as tailor made software is software written for the use in specific organisations such as the military and banks (basically from scratch)
Specialised software is wrtten soley for a specific task rather than a range of functions
Integrated software is a term for a computer program that includes all the major types of application
What are interfaces
Interfaces are basically how we interact with and use technology
What should interface have
An attractive design
be simple to use
have quick response time
have instructions that are easy to understand
have a consistant layout if there are multiple screens
Hardware interfaces
anything u physically touch like touchpad
Software interface
allow user to interact with the computer through interface
There are four main types of software interface
Command line interface
Menu driven interface- a list of options which u can choose what u want to do
Graphical user interface (WIMP Windows, icons, menu,pointer) very user friendly
pointers-
How to improve interfaces
WORKS EXACTLY THE SAME WAY EACH TIME THEY ARE USED
visually soothing and pleasing
When choosing a computer you should consider
what hardware is used
what software is used
what processing takes place
what human computer interface is used
which people are involved and what they do
what data is required
Types of computers
Workstation-
Supercomputer-
Mainframe- These are
Desktop systems
Mobile devices
Embedded system- only created for certain task example traffic light, dont need internet
Data
raw unprocessed facts
Information
processed data
Information system
system used to record data
Validation
is the computerised checking of input data for errors(data may be unreasonable or incomplete) before it is processed. It does not confirm the accuracy of the data
Method of data validation check
range check- data entered within a certain range
Reasonableness check- check to see if data obeys specified criteria
Data type check- correct type of date
Consistency check- checks the contents of two or more fields to make sure they make sense
Presence check- ensures data is actually entered
Format check- correct format
Length check- correct length of data is entered
check digit- detect data arising from transcription and also ensure the code originally produced by a computer are re entered in another computer correctly
Verification
is checking for mistakes such as transcription errors when one data is copied from one medium or device to another. Verification checks do not guaranteed that the entered data is correct, it only checks that the data entered matches the source document
Methods of Verification
Double entry- data is entered twice using a program that checks them against each other
visual checks- user checks to confirmed it written correctly
Data logging
sensor is input at regular intervals so the data can processed to provide analysis of environment
used by scienctist to automatically record changes in conditions
