Wednesday, October 20, 2010

Chapter 1: Our Digital Planet

Creating Communities on the Living Web
-MySpace creates an online community experience for young people
-Flickr creates a community for people to share pictures
Living in A Non-Digital World
-Computers are no longer a luxury but a commodity
-Computers and their applications are involved in all aspects of our daily life
Computers in perspective
-Every Computer in use today follows the basic plan laid out by Charles Babbage and Lady Lovelace
-The computer is an incredibly versatile tool
-It can compute your taxes or deploy a missile.
-All computers take in information called input and give out information called output
-The Computer's versatility is built upon its hardware (the physical part) Software (the instructions that tells hardware how to transform the input data into the necessary output.
-The first real computers: In 1939, Knrad Zuse completed the first programmable, general-purpose digital computer.
-At about the same time, the British government was assembling a top-secret team of mathematicians and engineers to crack Nazi military codes.
In 19943, the team led by mathematician Alan Turing and others completed Colossus, considered by many to be the first electronic digital computers.
-In 1939, Iowa State University professor John Atanasoff developed what could have been the first electronic digital computer, the Atanasoff-Berry Computer (ABC)
-In 1944, Thanks to one million grant from IBM, Harvard professor Howard Aiken developed the Mark I.
John Mauchly and J. Presper Eckert helped the US effort in World War II by constructing a machine to calculate trajectory tables for new guns.
-ENIAC: Electronic Numerical Integrator and Computer
-After the war, Mauchly and Eckert started a private company called Sperry and created UNIVAC I, the first general purpose commercial computer.
-Vacuum tubes were used in early computers.
-Transistors replaced vacuum tubes starting in 1956
-By mid-1960s transistors were replaced by integrated circuits.
-Integrated circuits brought:
  • increased reliability
  • Smaller size
  • higher speed
  • higher efficiency
  • lower cost
-In 1971, the first microprocessor was invented by Intel engineers.
-The personal computer revolution began in 1970: Apple, Commodore, Tandy
Desktop computers have not completely replaced computers, which have also evolved.
Embedded Computers
-Special purpose computer: dedicated computers that perform specific tasks such as controlling the temperature and humidity, monitoring your heart rate, monitoring your house security system
-The program is etched on silicon so it cannot be altered. This is called firmware.
Personal Computers: PCs serve a single user at a time. Common applications include: word processing, accounting, gaming, enjoying digital music and video
Workstations:
-High end desktop computers with massive computing power used for high-end interactive applications
-portable computers: machines that are not tied to the desktop such as notebooks and handheld computers.
Servers:
-computers designed to provide software and other resources to other computers over a network
Mainframes and Super Computers:
-Mainframes are used by large organizations, such as banks and airlines, for big computing jobs. They communicate with mainframe through terminals. Multiple communications at one time through process of time sharing
-Supercomputers: For power users who need access to the fastest most powerful computers made.
-The Emergence of Networks: to connect devices together and in the 1960s, Internet developed with backing of the US government.
-The Internet explosion-over a billion people with Internet access by the end of 2005
Electronic mail also known as E-Mail
World Wide Web-WWW
-led the Internets transformation from a text-only environment into a multimedia landscape incorporating pictures, animation, sounds, and video
Web Browsers
-programs that, in effect, serve as navigable Windows into the web
Hypertext Links
-Tie together millions of Web pages created by diverse authors.
Internet supports varied activities
-eBay used to make international transactions
-real-time multi player games.
To command or open something, you open brackets put the command in, and close the brackets.
To close something, you must open brackets, put a back slash, and close the brackets.
In the history of our society, we have had: an agricultural age, an industrial age, now we are in the information age
-more and more people earn their livings working with words, numbers, and ideas.
Explanations: Clarifying Technology
-Computer literacy is already improving our day to day lives and careers
Applications: computers in action
-Applications Enable you to use a computer for specific purposes.
Implications: Social and Ethical Issues
-The threat to personal privacy posed by large databases and computer networks
-The hazards of high-tech crime and the difficulty of keeping data secure
-The difficulty of defining and protecting intellectual property in an all digital age
-The threat of automation and the dehumanization of work
-The abuse of information as a tool of political and economic power
-The emergence of bio-digital technology
-The dangers of dependence on complex technology
Bio digital: using technology for science
Consequences of Bio-Digital Technology:
-we become so dependent on it that we begin to lose our own skills
- black outs
-computers taking over for humans-loss of jobs
-Computers have evolved at an incredible pace since Charles Babbage's plan for an Analytical Engine.
-Computers today come in all shapes ansizes, with specific types being wll-suited for particular jobs.
-Conneting to a network enhances the calue and power of a computer
  • Internet
  • WWW
  • Email

Wednesday, October 13, 2010

ITGS NOTES: File Management

File Management: Where is my Stuff?
-Files can be scattered all over the system which often makes data management difficult
-one solution to this problem is to organize data files logically
-Both Windows and the Mac support the notion of common system folders with self-explanatory name such as My Documents, My Pictures, and My Music
File Management Utilities
-View, rename, copy, move, and delete files and folders
-hierarchies help with organization
-help with locating a file
-get size, file typer, and last modification date
Managing Files from Applications
-Operations: Open, Save As, Save, and Close
Defragmentation
Software Piracy-illegal duplication of copyrighted software
-the software industry is a $50 billion a year busniess sector
-billions of dollars are lost each year to software pirates
-one-third of all software is illegally copied.
Applications and Interfaces:
-The WIMP(windows, icons, menus, and pointing devices) interface is easier to learn and use them

Sunday, October 10, 2010

Platforms and Compilers

Basic Need Doesn't Change, the Way we Satisfy it Changes.

Platform in terms of IT: Combination of hardware and software to run a program.
Example: Iphone Hardware, IOS Software
'This cellphone runs on this platform'
There are three layers of IT:
The bottom layer is Hardware and the Middle Layer is the Operating System. Together, these two create a platform. You use the Hardware and the Operating System to run an application, which is obviously the top layer.
Compilers/Interpreters:
-Computers are language-dependent. They only binary and the permutation of 'on' and 'off' gives us language.
-An interpreter takes information, does something to it and provides so the computer and I, the user, could understand
-There is one interpreter between the Hardware and the Operating System and there is one between the Operating System and the Application.
Java Language Platform: deployment to any platform
Cross Platform/PIM:
-2 platforms
-application that can work on multiple platforms
PIM: Platform Independent Model
Java Virtual Machine: First Compiler which can run on anything

Friday, October 1, 2010

ITGS Notes #9

Vertical Market and Custom Software
  • Tends to cost far more than mass-market applications
  • Job Specific Software
  • medical billings
  • library cataloging
  • legal reference software
  • restaurant management
  • single client software needs
System Software:
  • a class of software that includes the operating system and utility programs handles these details and hundreds of other tasks behind the scenes
"Originally Operating systems were envisioned as a way to handle one of the most complex input/output drives. But, the operating system quickly evolved into an all-encompassing bridge between your PC and the software you run on it." Ron White in How computers Work

Operating System Functions:
-supports multi-tasking
-manages virtual memory
-maintains file system
-responsible for authentication and authorization

What is the difference between authentication and authorization?
Authentication:
Authentication is a process of identifying a user based on their credentials(means user id and password).

Authorization:
Authorization is process of determining whether an authenticated user is allowed to access a specific resource or not.

What does the operating system do?

Utility Programs
  • -Serve as told for doing system maintenance and repairs that aren't automatically handled by the operating system
  • -Make it easier for users to
  • -copy files between storage devices
  • -repair damaged data files
  • -translate files so that different programs can read them
  • Guard against viruses and other potentially harmful programs
  • compress files so they can take up less disk space
  • perform other important tasks
  • Symantec Norton Utilities is a popular utility package that includes software tools for recovering damaged files repairing damaged disks and improving disk performance
Device Drivers
  • Small programs that enable I/O devise-keyboard, mouse, printer, and others-t communicate with the computer
Where the Operating System Lives:
  • some computers store their operating system in TOM
  • Others include only part of it in ROM
  • The remainder of the operating system is loaded into memory in  process called booting which occurs when you turn on the computer
Most of the time the operating system works behind the scenes
interacting with the operating system like interacting with an application can be intuitive or challenging and it depends on something called the use interface
The interface defines the look and feel of the computing experience from a human point of view
Desktop Operating Systems
-MS-DOS is a disk operating system in which the user interacts user characters such as letters, numbers, and symbols
Feature include:
-command line interface                          
-menu driven interface
Graphical User Interface:
-Mac OS was developed by Macintosh in 1984
-Microsoft Windows is now the most popular operating system
Multiple User Operating: UNIX and Linux
-UNIX was developed at Bell Labs before personal computers were available
-Linus was created by Linus Torvalds and continues to be a work in progress
UNIX allows a time sharing computer to communicate with several other computers or terminals at once
-Linux is free for anyone to use or improve
-UNIX remains the dominant operating system for Internet services
Some form of UNIX is available for personal computers work stations servers main frames and super computers.
Cross-platform applications such as Microsoft Office and Adobe Photoshop are programs that are availabe in similar vrsion for multiple platforms.
Mac Users can buy software emulation programs that:
-Create a simulated Windows