Computer Programs and Programming Languages
- Computer program is a series of instructions that directs a computer to perform tasks.
- Computer program is created by a programmer using programming language.
- Programming language is a set of words, abbreviations and symbols that enables a software developer to communicate instructions to a computer or mobile device.
Low-Level Languages
- Machine language is the first generation of programming languages
- The only language the computer directly recognizes.
- Assembly language is the second generation of programming languages.
- Programmer writes instructions using symbolic instruction codes.
- Source program contains the code to be converted to machine language.
Procedural Languages
- With a procedural language, a software developer writes instructions using English-like words that tell the computer what to accomplish and how to do it.
- C programming language is used to write many of today's programs.
Object-Oriented Programming Languages and Application Development Tools
- System developers use an object-oriented programming (OOP) language or object-oriented application development tool to implement objects in a program.
- Programs developed using OOP language have several advantages:
The objects can be reused in many systems, are designed for repeated use and become stable over time.
Developers create applications faster because they design programs using existing objects.
Work well in a RAD environment.
Most object-oriented application development tools are referred to as a integrated development environment (IDE) because they include tools for building graphical interfaces, an editor for entering program code, a compiler and/or interpreter and a debugger (to remove error).
Java
- Java is an object-oriented programming language developed by Sun Microsystems.
- The just-in-time (JIT) compiler converts the bytecode into machine-dependent code.
.NET
- The Microsoft .NET Framework is a set of technologies that allows almost any type of program to run on the Internet or an internal business network, as well as stand-alone computers and mobile devices.
- Features include:
Common language runtime (CLR)
Classes
C++
- C++ is an object-oriented programming language that is an extension of the C programming language.
- C# is based on C++ and was developed by Microsoft.
- F# combines the benefits of an object-oriented language with those of a functional language.
Visual Studio
- Visual studio contains a suite of object-oriented application development tools that assists software developers in building programs and apps for Windows or any OS that supports the Microsoft .NET Framework.
- Visual studio also includes a set of tools for developing programs and apps that work with Microsoft's Office suite.
- Visual Basic is based on the BASIC programming language.
- Visual C++ is based on C++.
- Visual C# combines the programming elements of C++ with an easier, rapid-development environment.
Visual programming language
- Visual programming language is a language that uses a visual or graphical interface for creating all source code.
Delphi
- Borland's Delphi is a powerful program development tool that is ideal for building large-scale enterprise and Web applications in a RAD environment.
PowerBuilder
- PowerBuilder is a powerful program development RAD tool.
- Best suited for Web-based, .NET and large-scale enterprise objects-oriented applications.
4GLs
- Fourth-generation language (4GL) is a nonprocedural language that enable users and software developers to access data in a database.
- One popular 4GL is SQL.
Classic programming languages
- These languages, which include BASIC, COBOL, FORTRAN and RPG, were more widely used in the past than they are today.
Application generators
- Application generator is a program that creates source code or machine code from a specification of the required functionality.
- Most often are bundled with or are included as part of a DBMS.
Macros
- Macro is a series of statements that instructs a program or app how to complete a task.
- User usually create a macro in one of two ways:
Record the macro, or
Write the macro
Web Development
HTML
- Hypertext Markup Language (HTML) is a special formatting language that software developers use to format documents for display on the web.
- Extensible Hypertext Markup Language (XHTML) is a markup language that allows website to be displayed more easily on mobile devices.
XML
- Extensible Markup Language (XML) is an increasingly popular format for sharing data that allows web developers to create tags that describe the structure of information.
- XML separates the webpage content from its format, allowing the browser to display the contents of a webpage in a form appropriate for the display device.
- Wireless devices use a subset of XML called WML.
- Wireless markup language (WML) allows web developers to design pages specifically for microbrowsers.
- Two applications of XML are the RSS 2.0 and ATOM specifications.
- Really simple syndication (RSS) and ATOM are specifications that content aggregators use to distribute content to subscribers.
Validate design
- Check for logic errors using test data.
Develop various sets of test data
Determine the expected result
Step through the algorithm
Compare the results
Repeat steps for each set of test data
Implement design
- Implementation of the design includes using a program development tool that assists the programmer by:
Generating or providing some or all code
Writing the code that translates the design into a computer program
Creating the user interface
- Extreme programming is a strategy where programmers immediately begin coding and testing solutions as soon as requirements are defined.
Test solution
- The goal of program testing is to ensure the program runs correctly and is error free.
- Errors include syntax errors and logic errors.
- Debugging the program involves removing the bugs.
- Beta is a program that has most or all of its features and functionality implemented.
Document solution
- In documenting the solution, the programmer performs two activities:
Review the program code
Review all the documentation
Sunday 16 October 2016
Chapter 12
Ongoing Activities
- Planning
- Analysis
- Design
- Implementation
- Operation, Support, and Security
Example for Planning
- Select team- required staff
- Resources
- Expectation/ Request from user
Example for Analysis
- Study of car park system available
- User requirement/ Priority
Example for Design
- Design layout, Features, software used(GUI)
Example for Implementation
- Build car park system
- User training
- Testing the system
Example for Operation, Support, and Security
- Maintenance- based on schedule
- Check Security
- Monitor Performance- daily activitie
Chapter 11
Computer Security Risks
- Computer security risk is any event or action that could cause a loss of or damage to computer or mobile device hardware, software, data, information or processing capability
- Cybercrime refers to online or Internet-based illegal acts such as distributing malicious software or committing identity theft
- Perpetrators of cybercrime:
Hacker refers to someone who accesses a computer or network illegally
Cracker is someone who accesses a computer or network illegally but has the intent of destroying data, stealing information or other malicious action
Script kiddie has the same intent as a cracker but does not have the technical skills and knowledge. Script kiddies often use prewritten hacking and cracking programs to break into computers and networks
Corporate spies have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information, or to help identify security risks in their own organisation
Unethical employees may break into their employer's computers for a variety of reasons
Cyberextortionist is someone who demands payment to stop an attack on an organisation's technology infrastructure
Cyberterrorist is someone who uses the Internet or network to destroy or damage computers for political reasons
Internet and Network Attacks
- Information transmitted over networks has a higher degree of security risk than information kept on an organisation's premises
- An online security service is a website that evaluates your computer to check for Internet and e-mail vulnerabilities
- Types of malware:
Virus - It affects, or infects, a computer or mobile device negatively by altering the way it works
Worm - It copies itself repeatedly using up resources and possibly shutting down the computer, device or network
Trojan horse - A program that hides within or looks like a legitimate program
Rootkit - A program that hides in a computer or mobile device and allows someone from a remote location to take full control of the computer or device
- Symptoms of infected computer:
OS runs much slower than usual
Available memory is less than expected
Files become corrupted
Screen displays unusual message or image
Music or unusual sound plays randomly
Existing programs and files disappear
Programs or files do not work properly
Unknown programs or files mysteriously appear
System properties change
OS does not start up
OS shuts down unexpectedly
- Botnet is a group of compromised computers or mobile devices connected to a network
- Denial of service attack (DoS attack) disrupt computer access to an Internet service
- Back door is a program or set of instructions in a program that allows users to bypass security controls
- Spoofing is a technique intruders use to make their network or Internet transmission appear legitimate
- Firewall is hardware and/or software that protects a network's resources from intrusion
- Intrusion detection software:
Analyses all network traffic
Assesses system vulnerabilities
identifies any unauthorized intrusions
Notifies network administrators of suspicious behavior patterns or system breaches
- Honeypot is vulnerable computer that is set up to entice intruder to break into it
- Unauthorized access is the use of a computer or network without permission
- Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities
- Safeguards against unauthorized access or use:
Have a written acceptable use policy (AUP)
Disable file and printer sharing
Use a firewall
Have an intrusion detection software
- Access control is a security measure that defines who can access a computer, device or network; when they can access it; and what actions they can take while accessing it
- Examples of access control:
User names and passwords
Passphrase
PIN
CAPTCHA
- Possessed object is any item that you must carry to gain access to a computer facility
- Biometric device authenticates a person's identity by translating a personal characteristic into a digital code that is compared with a digital code in a computer
- Digital forensics is the discovery, collection and analysis of evidence found on a computers and networks
- Areas use digital forensics including:
Law enforcement
Criminal prosecutors
Military intelligence
Insurance agencies
Information security departments
Hardware Theft and Vandalism
- Hardware theft is the act of stealing computer equipment
- Hardware vandalism is the act of defacing or destroying computer equipment
- Safeguards:
Physical access controls (locked doors and windows)
Alarm systems
Physical security devices (cables and locks)
Device-tracking app
Password, possessed objects and biometrics
Software Theft
- Software theft occurs when someone:
Steals software media
Intentionally erases programs
Illegally registers and/or activities a programs
Illegally copies a program
- Typical conditions of a Single-User License Agreement:
Permitted to install the software on one computer; make one copy of the software as a backup; remove the software from the user's computer before give or sell the software to another individual
Not permitted to install the software on a network; give copies to friends and colleagues while continuing to use the software; export the software; rent or lease the software
Information Theft
- Information theft occurs when someone steals personal or confidential information
- Encryption is the process of converting data that is readable by humans into encoded characters to prevent unauthorized access
- Back up a file means to make a copy of it
- Off-site backups are stored in a location separated from the computer site. Eg. cloud storage
- Backup methods:
Full backup - Copies all of the files on a media in the computer
Differential backup - Copies only the files that have changed since the last full backup
Incremental backup - Copies only the files that have changed since the last full or incremental backup
Selective backup - Users choose which folders and files to include in a backup
Continuous data protection (CDP) - All data is backed up whenever a change is made
Cloud backup - Files are backed up to the cloud as they change
- Three-generation backup policy preserve three copies of important files
Grandparent - The oldest copy of the file
Parent - The second oldest copy of the file
Child - The most recent copy of the file
Wireless Security
- Wireless access poses additional security risks
- Safeguards:
A wireless access point should not broadcast an SSID
Change the default SSID
Configure a WAP so that only certain devices can access it
Use WPA or WPA2 security standards
Ethics and Society
- Computer ethics are the moral guidelines that govern the use of computers and information systems
- Information accuracy is a concern today. Do not assume the information on the Web is correct
- Intellectual property rights are the rights o which creators are entitled for their work
- Code of conduct is a written guideline that helps determine whether a specification is ethical/unethical or allowed/not allowed
- Spam is an unsolicited e-mail message or newsgroup posting
- E-mail filtering blocks e-mail messages from designated sources
- Anti-spam programs attempt to remove spam before it reaches your inbox
- Phishing is a scam which a perpetrator sends an official looking email message that attempts to obtain your personal and/or financial information
- Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing
- Social engineering is defined as gaining unauthorized access to or obtaining confidential information by taking advantage of the trusting human nature of some victims and the naivety of others
- Employee monitoring involves the use of computers to observe, record and review an employee's use of a computer
- Content filtering is the process of restricting access to certain material
- Web filtering software is a program that restricts access to specified websites
- Computer security risk is any event or action that could cause a loss of or damage to computer or mobile device hardware, software, data, information or processing capability
- Cybercrime refers to online or Internet-based illegal acts such as distributing malicious software or committing identity theft
- Perpetrators of cybercrime:
Hacker refers to someone who accesses a computer or network illegally
Cracker is someone who accesses a computer or network illegally but has the intent of destroying data, stealing information or other malicious action
Script kiddie has the same intent as a cracker but does not have the technical skills and knowledge. Script kiddies often use prewritten hacking and cracking programs to break into computers and networks
Corporate spies have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information, or to help identify security risks in their own organisation
Unethical employees may break into their employer's computers for a variety of reasons
Cyberextortionist is someone who demands payment to stop an attack on an organisation's technology infrastructure
Cyberterrorist is someone who uses the Internet or network to destroy or damage computers for political reasons
Internet and Network Attacks
- Information transmitted over networks has a higher degree of security risk than information kept on an organisation's premises
- An online security service is a website that evaluates your computer to check for Internet and e-mail vulnerabilities
- Types of malware:
Virus - It affects, or infects, a computer or mobile device negatively by altering the way it works
Worm - It copies itself repeatedly using up resources and possibly shutting down the computer, device or network
Trojan horse - A program that hides within or looks like a legitimate program
Rootkit - A program that hides in a computer or mobile device and allows someone from a remote location to take full control of the computer or device
- Symptoms of infected computer:
OS runs much slower than usual
Available memory is less than expected
Files become corrupted
Screen displays unusual message or image
Music or unusual sound plays randomly
Existing programs and files disappear
Programs or files do not work properly
Unknown programs or files mysteriously appear
System properties change
OS does not start up
OS shuts down unexpectedly
- Botnet is a group of compromised computers or mobile devices connected to a network
- Denial of service attack (DoS attack) disrupt computer access to an Internet service
- Back door is a program or set of instructions in a program that allows users to bypass security controls
- Spoofing is a technique intruders use to make their network or Internet transmission appear legitimate
- Firewall is hardware and/or software that protects a network's resources from intrusion
- Intrusion detection software:
Analyses all network traffic
Assesses system vulnerabilities
identifies any unauthorized intrusions
Notifies network administrators of suspicious behavior patterns or system breaches
- Honeypot is vulnerable computer that is set up to entice intruder to break into it
- Unauthorized access is the use of a computer or network without permission
- Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities
- Safeguards against unauthorized access or use:
Have a written acceptable use policy (AUP)
Disable file and printer sharing
Use a firewall
Have an intrusion detection software
- Access control is a security measure that defines who can access a computer, device or network; when they can access it; and what actions they can take while accessing it
- Examples of access control:
User names and passwords
Passphrase
PIN
CAPTCHA
- Possessed object is any item that you must carry to gain access to a computer facility
- Biometric device authenticates a person's identity by translating a personal characteristic into a digital code that is compared with a digital code in a computer
- Digital forensics is the discovery, collection and analysis of evidence found on a computers and networks
- Areas use digital forensics including:
Law enforcement
Criminal prosecutors
Military intelligence
Insurance agencies
Information security departments
Hardware Theft and Vandalism
- Hardware theft is the act of stealing computer equipment
- Hardware vandalism is the act of defacing or destroying computer equipment
- Safeguards:
Physical access controls (locked doors and windows)
Alarm systems
Physical security devices (cables and locks)
Device-tracking app
Password, possessed objects and biometrics
Software Theft
- Software theft occurs when someone:
Steals software media
Intentionally erases programs
Illegally registers and/or activities a programs
Illegally copies a program
- Typical conditions of a Single-User License Agreement:
Permitted to install the software on one computer; make one copy of the software as a backup; remove the software from the user's computer before give or sell the software to another individual
Not permitted to install the software on a network; give copies to friends and colleagues while continuing to use the software; export the software; rent or lease the software
Information Theft
- Information theft occurs when someone steals personal or confidential information
- Encryption is the process of converting data that is readable by humans into encoded characters to prevent unauthorized access
- Back up a file means to make a copy of it
- Off-site backups are stored in a location separated from the computer site. Eg. cloud storage
- Backup methods:
Full backup - Copies all of the files on a media in the computer
Differential backup - Copies only the files that have changed since the last full backup
Incremental backup - Copies only the files that have changed since the last full or incremental backup
Selective backup - Users choose which folders and files to include in a backup
Continuous data protection (CDP) - All data is backed up whenever a change is made
Cloud backup - Files are backed up to the cloud as they change
- Three-generation backup policy preserve three copies of important files
Grandparent - The oldest copy of the file
Parent - The second oldest copy of the file
Child - The most recent copy of the file
Wireless Security
- Wireless access poses additional security risks
- Safeguards:
A wireless access point should not broadcast an SSID
Change the default SSID
Configure a WAP so that only certain devices can access it
Use WPA or WPA2 security standards
Ethics and Society
- Computer ethics are the moral guidelines that govern the use of computers and information systems
- Information accuracy is a concern today. Do not assume the information on the Web is correct
- Intellectual property rights are the rights o which creators are entitled for their work
- Code of conduct is a written guideline that helps determine whether a specification is ethical/unethical or allowed/not allowed
- Spam is an unsolicited e-mail message or newsgroup posting
- E-mail filtering blocks e-mail messages from designated sources
- Anti-spam programs attempt to remove spam before it reaches your inbox
- Phishing is a scam which a perpetrator sends an official looking email message that attempts to obtain your personal and/or financial information
- Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing
- Social engineering is defined as gaining unauthorized access to or obtaining confidential information by taking advantage of the trusting human nature of some victims and the naivety of others
- Employee monitoring involves the use of computers to observe, record and review an employee's use of a computer
- Content filtering is the process of restricting access to certain material
- Web filtering software is a program that restricts access to specified websites
Chapter 10
- Define the term, database, and explain how a database interacts with data and information
- Define the term, data integrity, and describe the qualities of valuable information
- Discuss the terms character, field, record, and file
- Describe file maintenance techniques and validation techniques
- Differentiate between a file processing approach and the database approach
- Discuss the functions common to most database management systems
- Explain how to access Web databases
- Describe characteristics of relational, object-oriented, and multidimensional databases
- Identify database design guidelines and discuss the responsibilities of database analysts and administrators
Step of How a School's Admissions Department Might Process New Student Data into Information
- Admin take student picture
- Student data stored into database
- computer extract data-advisor name, schedule appointment, course taken
- comfirmation of advisiry appointment
- Admin give student ID with expired date
The Hierarchy of Data
- Character
- field
- records
- files
Common Data Type Include
- Text
- Numeric
- AutoNumber
- Currency
- Date
- Memo
File maintenance refers to the procedures that keep data currnt
- Adding records
- Modifying records
- Deleting records
Validation compares data with a set of riles or values to find out of the data is correct
- Alphabetic / Numeric Check
- Range check
- Consistency Check
- Completeness Check
- Check Digit
- Other Check
Chapter 8
The Two Types Of Software
A stand-alone operating system is a complete operating system that works on a desktop or notebook computer. A network operating system (also called network OS or NOS) is an operating system that supports a network. A network is a collection of computers and devices connected together via communications media and devices such as cables, telephone lines, and modems. In some networks, the server is the computer that controls access to the hardware and software on a network and provides a centralized storage area. The other computers on the network, called clients, rely on the server(s) for resources.
Two types of software are application software and system software. Application software consists of programs that perform specific tasks for users, such as a word processing program, e-mail program, or Web browser. System software consists of the programs that control the operations of a computer and its devices. The two types of system software are operating systems and utility programs. An operating system (OS) is a set of programs containing instructions that coordinate all the activities among computer hardware devices. A utility program performs a specific task, usually related to managing a computer, its devices, or its programs.
Understand The Startup Process For A Personal Computer
Booting is the process of starting or restarting a computer. When you turn on the computer, the power supply sends an electrical signal to devices located in the system unit. The processor chip resets itself and looks for the ROM chip that contains the BIOS (basic input/output system), which is firmware that holds the startup instructions. The BIOS executes the power-on self test (POST) to make sure hardware is connected properly and operating correctly. The POST results are compared with data in a CMOS chip on the motherboard. If the POST completes successfully, the BIOS searches for specific operating system files called system files. Once located, the boot drive (the drive from which your personal computer starts), loads the system files from storage (the hard disk – usually drive C) into memory (RAM) and executes them. Next, the kernel of the operating system loads into memory and takes control of the computer. The operating system loads configuration information. In Windows XP, the registry consists of several file that contain the system configuration information. When complete, the Windows XP desktop and icons display, and programs in the StartUp folder are executed.
Discuss The Purpose Of The Following Utilities: File Viewer, File Compression, Diagnostic, Uninstaller, Disk Scanner, Disk Defragmenter, Backup, And Screen Saver
Know The Difference Between Stand-Alone Operating Systems And Network Operating System
A stand-alone operating system is a complete operating system that works on a desktop or notebook computer. A network operating system (also called network OS or NOS) is an operating system that supports a network. A network is a collection of computers and devices connected together via communications media and devices such as cables, telephone lines, and modems. In some networks, the server is the computer that controls access to the hardware and software on a network and provides a centralized storage area. The other computers on the network, called clients, rely on the server(s) for resources.
Chapter 7
Stand-Alone Operating System
- A complete OS that works on a desktop computer, notebook computer or mobile computing device
- Windows 10 is Microsoft's fastest, most efficient OS to date and is available in multiple editions:
Windows 10 Home
Windows 10 Pro
Windows 10 Enterprise
Windows 10 Mobile
- Windows 10 provides programs such as:
Alarms & Clock
Weather
Voice Recorder
Output
- Output is data that has been processed into a useful form
Output Device
- It is any type of hardware component that conveys information to one or more people
- Eg: Display devices, printers, speakers, headphones, earbuds, data projectors, interactive whiteboards, force-feedback game controllers, tactile output
Display Devices
- It visually conveys text, graphics and video information
- Eg: LCD monitor
- Liquid crystal display (LCD) uses a liquid compound to present information on a display device
Active-matrix display - Uses a grid of transistors and capacitors with the ability to hold charge for a limited period of time
Passive-matrix display - Uses a simple conductive grid to apply supply voltage to pixels on the display
- The quality of a LCD screen depends primarily on:
Resolution - Number of horizontal and vertical pixels in a display
Response time
Brightness
Dot pitch - Distance between sub-pixels
Contrast ratio
- Graphics processing unit (GPU) controls the manipulation and display of graphics on a display device
- LCD monitors use a digital signal and should plug into DVI port, HDMI port or DisplayPort
- Plasma monitors are display devices that use gas plasma technology and offer screen sizes up to 150"
- Digital television (DTV) offers a crisper, higher quality output
- HDTV is the most advanced form of digital television
- Cathode ray tube (CRT) monitor is a desktop monitor that contains a cathode-ray tube
Printers
- Printer produces text and graphics on a physical medium
- Nonimpact printer forms characters and graphics on a piece of a paper without actually striking the paper
Ink-jet printers - Forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper
Photo printers - Produces color photo-lab-quality pictures. Use ink-jet technology
Laser printers - High-speed, high-quality, color / B&W
- A complete OS that works on a desktop computer, notebook computer or mobile computing device
- Windows 10 is Microsoft's fastest, most efficient OS to date and is available in multiple editions:
Windows 10 Home
Windows 10 Pro
Windows 10 Enterprise
Windows 10 Mobile
- Windows 10 provides programs such as:
Alarms & Clock
Weather
Voice Recorder
Output
- Output is data that has been processed into a useful form
Output Device
- It is any type of hardware component that conveys information to one or more people
- Eg: Display devices, printers, speakers, headphones, earbuds, data projectors, interactive whiteboards, force-feedback game controllers, tactile output
Display Devices
- It visually conveys text, graphics and video information
- Eg: LCD monitor
- Liquid crystal display (LCD) uses a liquid compound to present information on a display device
Active-matrix display - Uses a grid of transistors and capacitors with the ability to hold charge for a limited period of time
Passive-matrix display - Uses a simple conductive grid to apply supply voltage to pixels on the display
- The quality of a LCD screen depends primarily on:
Resolution - Number of horizontal and vertical pixels in a display
Response time
Brightness
Dot pitch - Distance between sub-pixels
Contrast ratio
- Graphics processing unit (GPU) controls the manipulation and display of graphics on a display device
- LCD monitors use a digital signal and should plug into DVI port, HDMI port or DisplayPort
- Plasma monitors are display devices that use gas plasma technology and offer screen sizes up to 150"
- Digital television (DTV) offers a crisper, higher quality output
- HDTV is the most advanced form of digital television
- Cathode ray tube (CRT) monitor is a desktop monitor that contains a cathode-ray tube
Printers
- Printer produces text and graphics on a physical medium
- Nonimpact printer forms characters and graphics on a piece of a paper without actually striking the paper
Ink-jet printers - Forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper
Photo printers - Produces color photo-lab-quality pictures. Use ink-jet technology
Laser printers - High-speed, high-quality, color / B&W
Thermal printers - Generates images by pushing electrically heated pins against the heat-sensitive paper. Eg: Thermal wax-transfer printer, dye-sublimation printer
Mobile printers - Small, lightweight, battery-powered printer that allows a mobile user to print from a notebook computer, smartphone or other mobile device
Label printers - Small printer that prints on adhesive-type material
Postage printers - Prints postage stamps
Plotters - Produce high-quality drawings
Large-format printers - Create photo-realistic quality color prints on a larger scale
- Multifunction peripheral (MFP) is a single device that prints, scans, copies and in some cases faxes
- Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper
Dot-matrix printer - Produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon
Line printer - Prints an entire line at a time
Speakers, Headphones & Earbuds
- It is an audio output device produces music, speech or other sounds
- Users attach speakers to their computers to:
Generate higher-quality sounds for playing games
Interact with multimedia presentations
Listen to music
View movies
- Headphones are speakers that cover or placed outside of ear
- Earbuds rest inside ear canal
- Some speakers are specifically designed to play audio from a portable media player. Eg: Wireless speakers.
- Voice output occurs when you hear a person's voice or when the computer talks to you through the speakers
- Some website dedicate themselves to providing voice output
- Voice output often works with voice input
- VoIP uses voice output and voice input
Data Projector
- A device that takes the text and images displaying on a computer screen and projects them on a larger screen
Interactive whiteboard
- A touch-sensitive device, resembling a dry-erase board, that displays the image on a connected computer screen
Force-feedback Game Controller
- It sends resistance to the device in response to actions of the user
Tactile Output
- It provides the user with a physical response from the device
Chapter 6
- Define input and differentiate among a program, command, and user response
- Identify the keys and buttons commonly found on desktop computer keyboards, and describe how keyboards for mobile computers and devices differ from desktop computer keyboards
- Describe different mouse types
- Describe various types of touch screens and explain how a touch-sensitive pad works
- Describe various types of pen input, and identify other types of input for smart phones
- Summarize the purpose of various game controllers
- Explain how resolution affects the quality of a picture captured on a digital camera
- Describe the uses of voice recognition, Web cams, and video conferencing
- Discuss how various scanners and reading devices work
- Summarize the various biometric devices
- Discuss how POS terminals, automated teller machines, and DVD kiosks work
- Identify alternative input devices for physically challenged users
What is Input?
- Input is any data and instructions entered into the memory of a computer
- Instructions can be entered into the computer in the form of programs, commands, and user responses
- An input device is any hardware component that allows users to enter data and instructions into a computer
What is a Keyboard?
- A keyboard is an input device that contains keys users press to enter data and instructions into a computer
- Most desktop computer keyboards have between 101 and 105 keys
- Most desktop computer keyboards have a numeric keypad on the right side of the keyboard
- Most desktop computer keyboards have function keys, CTRL keys, ALT keys, and arrow keys
- The insertion point, also known as the cursor, is a symbol on the screen that indicates where the next character you type will appear
- An ergonomic keyboard has a design that reduces the chance of wrist and hand injuries
- Ergonomics incorporates comfort, efficiency, and safety into the design of the workplace
- Keyboards on mobile devices typically are smaller and/or have fewer keys
- Some phones have predictive text input, which saves time when entering text using the phone’s keypad
What is a Pointing Device?
- A pointing device is an input device that allows a user to control a pointer on the screen
- A pointer is a small symbol on the screen whose location and shape change as a user moves a pointing device
- A mouse is a pointing device that fits under the palm of your hand comfortably
- A mouse can be wired or wireless
What is Voice Device?
- Voice input is the process of entering input by speaking into a microphone
- Voice recognition is the computer’s capability of distinguishing spoken words
- Audio input is the process of entering any sound into the computer
- Music production software allows users to record, compose, mix, and edit music and sounds
- Video input is the process of capturing full-motion images and storing them on a computer’s storage medium
- A Web cam is a type of digital video camera that enables a user to capture video and still images
- A Web cam is a type of digital video camera that enables a user to send e-mail messages with video attachments
- A Web cam is a type of digital video camera that enables a user to add live images to instant messages
- A Web cam is a type of digital video camera that enables a user to broadcast live images over the Internet
- A video conference is a meeting between two or more geographically separated people
Chapter 5
System Software
- It consists of the programs that control or maintain the operations of the computer and its devices
- Eg: Operating system (OS), utility programs
Operating System (OS)
- It is a set of programs containing instructions that work together to coordinate all the activities among computer hardware resources
- Activities such as:
Start and shut down a computer
Provide a user interface
Manage programs
Manage memory
Coordinate tasks
Configure devices
Establish an internet connection
Monitor performance
Provide utilities
Automatically update
Control a network
Administer security
OS Functions
- Booting is the process of starting or restarting a computer
- 2 types of booting:
Cold boot - Turning on a computer that has been powered off completely
Warm boot - Using the operating system to restart a computer
- A boot device is the drive from which your computer starts.
- A computer can start from a boot disk
- Boot disk is a removable digital data storage medium (CD-ROMs, USB flash drives, hard disks ) from which a computer can load and run an OS or utility program
- A recovery disc contains a few system files that will start the computer
- Recovery disc contains a backup of the original factory condition a computer as configured by an original equipment manufacturer (OEM)
- Recovery disk can also be created by an end-user which contains a favored condition of a computer
- An OS includes various shut down options:
Sleep - This mode saves any open documents and programs to RAM, turns off all unneeded functions and then places the computer in a low-power state
Hibernate - This mode saves any open documents and programs to a hard disk before removing power from the computer
- User interface controls how you enter data and instructions and how information is displayed on the screen
- With graphical user interface (GUI), a user interacts with menus and visual images
- With command-line interface, a user uses the keyboard to enter data and instructions
- Ways an OS handles programs directly affects its productivity:
Single use and multiuser
Single tasking and multitasking
Foreground and background
Preemptive multitasking - It works on a time sharing feature, where each process may be allocated equal shares of computing resources
Multiprocessing
- Memory management optimizes the use of RAM
- Virtual memory is a portion of a storage medium functioning as additional RAM
- OS determines the order in which task are processed
- Driver is a small program that tells the OS how to communicate with a specific device
- Plug & Play automatically configures new devices as you install them
- OS typically provide a means to establish internet connections
- Performance monitor is a program that assesses and reports information about various computer resources and devices
- OS often provide users with the capability of:
Manage files
Search for files
View images
Secure a computer
Uninstall programs
Clean up disks
Defragment disks
Diagnose problems
Backup files and disks
Setting up screen savers
- Automatic update automatically provides updates to the program
- Some OS are designed to work with server on a network
- Server OS organizes and coordinates how multiple users access and share resources on a network
- A network administrator uses the server operating system to:
Add and remove users, computers and other devices
Install software and administer network security
- Each user has a user account
User ID identifies a specific user
Password is a private combination of characters associated with the user name
Store
Cortana
Microsoft Edge
- Macintosh OS has set the standard for OS ease of use
- Mac OS X is the latest version
- UNIX is a multitasking OS developed in the early 1970s
- Linux is an open-source, popular, multitasking UNIX-type OS
Server OS
Windows Server 2008
Linux
Solaris
Netware
- Windows Server 2008 is an upgrade to Windows Server 2003. Has multiple editions. Most editions include Hyper-V, a virtualization technology
- Virtualization is the practice of sharing or pooling computing resources
Embedded OS
- It resides on a ROM chip on a mobile device or consumer electronic device
- Eg: Windows Embedded CE, Windows Phone, Palm OS, iOS, BlackBerry OS, Android, Embedded Linux, Symbian OS
Utility Programs
- It is a type of system software that allows a user to perform maintenance-type tasks
- File manager is a utility that performs functions related to file management. It:
Display a list of files
Organise files in folders
Copy, rename, delete, move and sort files & folders
Create shortcuts
- Search utility is a program that attempts to locate a file on your computer based on criteria user specify
- Image viewer allows users to display, copy & print the contents of a graphics file
- Uninstaller removes a program, as well as any associated entries in the system files
- Disk cleanup utility searches for and removes unnecessary files, such as:
Downloaded program files
Temporary internet files
deleted files
Unused program files
- Disk defragmenter reorganizes the files and unused space an a computer's hard disk so that the OS accesses data more quickly and programs run faster
- Backup utility allows users to copy files to another storage medium
- Restore utility reverses the process and returns backed up files to their original form
- Screen saver causes a display device's screen to show a moving image or blank screen if no activity occurs for a specified time
- Personal firewall detects and protects a personal computer from unauthorized intrusions
- Virus describes a potentially damaging computer program that affects a computer negatively
- Worm copies itself repeatedly in memory or over a network
- Torjan horse hides within or looks like a legitimate program
- Antivirus program protects a computer against viruses
Chapter 4
- Differentiate among various styles of system units on desktop computers, notebook computers, and mobile devices
- Identify chips, adapter cards, and other components of a motherboard
- Describe the control unit and arithmetic logic unit components of a processor, and explain the four steps in a machine cycle
- Identify characteristics of various personal computer processors on the market today, and describe the ways processors are cooled
- Define a bit and describe how a series of bits represents data
- Explain how program instructions transfer in and out of memory
- Differentiate among the various types of memory
- Describe the purpose and types of expansion slots and adapter cards, and differentiate among slots for various removable flash memory devices
- Differentiate between a port and a connector, and explain the differences among a USB port, FireWire port, Bluetooth port, SCSI port, eSATA port, IrDA port, serial port, and MIDI port
- Describe the types of buses in a computer
- Explain the purpose of a power supply and describe how it keeps cool
- Understand how to clean a system unit on a computer or mobile device
What is a System Unit ?
- The system unit is a case that contains electronic components of the computer used to process data
- The inside of the system unit on a desktop personal computer includes Drive Bay(s), Power Supply, Sound Card, Video Card, Processor, Memory.
- The main circuit board of the system unit is Motherboard
- A computer chip contains integrated circuits
What is Processor ?
- The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer
- Contain a control unit and an arithmetic logic unit (ALU)
- The control unit is the component of the processor that directs and coordinates most of the operations in the computer
- The arithmetic logic unit (ALU) performs arithmetic, comparison, and other operations
What is Memory?
Dynamic RAM (DRAM)
Static RAM (SRAM)
Magnetoresistive RAM (MRAM)
- Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data
- Stores three basic categories of items. Example [The operating system and other system software, Application programs, Data being processed and the resulting information]
- Each location in memory has an address
- Memory size is measured in kilobytes (KB or K), megabytes (MB), gigabytes (GB), or terabytes (TB)
- The system unit contains two types of memory which are Volatile memory and Nonvolatile memory
- Volatile memory - Loses its contents when power is turned off. Example includes RAM
- Nonvolatile memory - Does not lose contents when power is removed. Examples include ROM, flash memory, and CMOS
There are some type of basic types of RAM chips exist
Tuesday 6 September 2016
1/9/16
juz finish chapter 2 today
i learn internert what i use many year but dont know what is it@@
these are what i learn in chapter 2:
i)identify a URL
ii)describe the types of Web pages
iii)recognize Web pages
iv)explain how e-mail,FTP,chat room,chat and instant messaging work
v)coming soon~
ms wan suddenly tell us today is her birthday,then we sing the happy birthday song to ms immediately,its fun and happy today✧٩(ˊωˋ*)و✧
Monday 29 August 2016
29/9/16
today is the first day for this semester,its oso the first day i learn the CA,i feel its a fun course.I will do my best in this course╮(‵▽′)╭
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