types of computers


A microcomputer is a computer that has a microprocessor chip as its CPU. They are often called personal computers because they are designed to be used by one person at a time. Personal computers are typically used at home, at school, or at a business. Popular uses for microcomputers include word processing, surfing the web, sending and receiving e-mail, spreadsheet calculations, database management, editing photographs, creating graphics, and playing music or games.

Personal computers come in two major varieties, desktop computers and laptop computers:

Desktop computers are larger and not meant to be portable. They usually sit in one place on a desk or table and are plugged into a wall outlet for power. The case of the computer holds the motherboard, drives, power supply, and expansion cards. This case may lay flat on the desk, or it may be a tower that stands vertically (on the desk or under it). The computer usually has a separate monitor (either a CRT or LCD) although some designs have a display built into the case. A separate keyboard and mouse allow the user to input data and commands.    

Desktop personal computer

Laptop or notebook computers are small and lightweight enough to be carried around with the user. They run on battery power, but can also be plugged into a wall outlet. They typically have a built-in LCD display that folds down to protect the display when the computer is carried around. They also feature a built-in keyboard and some kind of built-in pointing device (such as a touch pad).

While some laptops are less powerful than typical desktop machines, this is not true in all cases. Laptops, however, cost more than desktop units of equivalent processing power because the smaller components needed to build laptops are more expensive.

PDAs and Palmtop Computers


Laptop personal computer

A Personal Digital Assistant (PDA) is a handheld microcomputer that trades off power for small size and greater portability. They typically use a touch-sensitive LCD screen for both output and input (the user draws characters and presses icons on the screen with a stylus). PDAs communicate with desktop computers and with each other either by cable connection, infrared (IR) beam, or radio waves. PDAs are normally used to keep track of appointment calendars, to-do lists, address books, and for taking notes.

A palmtop or handheld PC is a very small microcomputer that also sacrifices power for small size and portability. These devices typically look more like a tiny laptop than a PDA, with a flip-up screen and small keyboard. They may use Windows CE or similar operating system for handheld devices.

Some PDAs and palmtops contain wireless networking or cell phone devices so that users can check e-mail or surf the web on the move.



Personal Digital Assistant

Palmtop computer

A workstation is a powerful, high-end microcomputer. They contain one or more microprocessor CPUs. They may be used by a single-user for applications requiring more power than a typical PC (rendering complex graphics, or performing intensive scientific calculations).

Alternately, workstation-class microcomputers may be used as server computers that supply files to client computers over a network. This class of powerful microcomputers can also be used to handle the processing for many users simultaneously who are connected via terminals; in this respect, high-end workstations have essentially supplanted the role of minicomputers (see below).

Note! The term “workstation” also has an alternate meaning: In networking, any client computer connected to the network that accesses server resources may be called a workstation. Such a network client workstation could be a personal computer or even a “workstation” as defined at the top of this section. Note: Dumb terminals are not considered to be network workstations (client workstations on the network are capable of running programs independently of the server, but a terminal is not capable of independent processing).

There are classes of computers that are not microcomputers. These include supercomputers, mainframes, and minicomputers.



Workstation computer

A minicomputer is a multi-user computer that is less powerful than a mainframe. This class of computers became available in the 1960’s when large scale integrated circuits made it possible to build a computer much cheaper than the then existing mainframes (minicomputers cost around $100,000 instead of the $1,000,000 cost of a mainframe).

The niche previously filled by the minicomputer has been largely taken over by high-end microcomputer workstations serving multiple users (see above).


A mainframe computer is a large, powerful computer that handles the processing for many users simultaneously (up to several hundred users). The name mainframe originated after minicomputers appeared in the 1960’s to distinguish the larger systems from the smaller minicomputers.

Users connect to the mainframe using terminals and submit their tasks for processing by the mainframe. A terminal is a device that has a screen and keyboard for input and output, but it does not do its own processing (they are also called dumb terminals since they can’t process data on their own). The processing power of the mainframe is time-shared between all of the users. (Note that a personal computer may be used to “emulate” a dumb terminal to connect to a mainframe or minicomputer; you run a program on the PC that pretends to be a dumb terminal).

Mainframes typically cost several hundred thousand dollars. They are used in situations where a company wants the processing power and information storage in a centralized location. Mainframes are also now being used as high-capacity server computers for networks with many client workstations.



Mainframe computer (this IBM z-series computer is about 6 feet tall)

A supercomputer is a mainframe computer that has been optimized for speed and processing power. The most famous series of supercomputers were designed by the company founded and named after Seymour Cray. The Cray-1 was built in the 1976 and installed at Los Alamos National Laboratory. Supercomputers are used for extremely calculation-intensive tasks such simulating nuclear bomb detonations, aerodynamic flows, and global weather patterns. A supercomputer typically costs several million dollars.

Recently, some supercomputers have been constructed by connecting together large numbers of individual processing units (in some cases, these processing units are standard microcomputer hardware).

Please note: All of this talk of which computers are more powerful than others (i.e., mainframes are more powerful than minicomputers, which are more powerful than microcomputers) is relative for any particular moment in time. However, all classes of computers are becoming more powerful with time as technology improves. The microprocessor chip in a handheld calculator is more powerful than the ENIAC was, and your desktop computer has more processing power than the first supercomputers did.

Microprocessors Everywhere


Supercomputer (this one is a Cray-2 from the 1980’s)

Computers are, in fact, all around you. Microprocessor chips are found in many electronic devices (in your iPod, in your DVD player, in your microwave, in your car, in your phone). These are special-purpose computers that run programs to control the equipment and optimize its performance.
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different types of computer infection

  • Viruses – A virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.
  • E-mail viruses – An e-mail virus travels as an attachment to e-mail messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim’s e-mail address book. Some e-mail viruses don’t even require a double-click — they launch when you view the infected message in the preview pane of your e-mail software.
  • Trojan horses – A Trojan horse is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk). Trojan horses have no way to replicate automatically.
  • Worms – A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.
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what is a computer cookie?

A computer cookie is a small text file which contains a unique ID tag, placed on your computer by a website. The website saves a complimentary file with a matching ID tag. In this file various information can be stored, from pages visited on the site, to information voluntarily given to the site. When you revisit the site days or weeks later, the site can recognize you by matching the cookie on your computer with the counterpart in its database.

There are two types of computer cookies: temporary and permanent. Temporary cookies, also called session cookies, are stored temporarily in your browser’s memory and are deleted as soon as you end the session by closing the browser. Permanent cookies, also called persistent cookies, are stored permanently on your computer’s hard drive and, if deleted, will be recreated the next time you visit the sites that placed them there.

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making a powerpoint more effective

Preparing a talk always takes far longer than you anticipate.  Start early!

  • Write a clear statement of the problem and its importance.
  • Research. Collect material which may relate to the topic.
  • Tell a story in a logical sequence.
  • Stick to the key concepts. Avoid description of specifics and unnecessary details. 
  • If you are making a series of points, organize them from the most to the least important. The less important points can be skipped if you run short of time.
  • Keep your sentences short, about 10-20 words each is ideal. This is the way people usually talk.
  • Strive for clarity. Are these the best words for making your point? Are they unambiguous? Are you using unfamiliar jargon or acronyms?

Preparing Your Slides:

Presentation Design

  • Don’t overload your slides with too much text or data.
  • FOCUS. In general, using a few powerful slides is the aim.
  • Let the picture or graphic tell the story. Avoid text.
  • Type key words in the PowerPoint Notes area listing what to say when displaying the slide. The notes are printable.
  • Number your slides and give them a title.
  • Use the “summary slide” feature in slide sorter view to prepare an Agenda or Table of Contents slide.
  • Prepare a company logo slide for your presentation.
  • You can add a logo and other graphics to every slide using the slide master feature.
  • Proof read everything, including visuals and numbers.
  • Keep “like” topics together
  • Strive for similar line lengths for text.

Visual elements

  • A font size of 28 to 34 with a bold font is recommended for subtitles. The title default size is 44. Use a san serif font for titles.
  • Use clear, simple visuals. Don’t confuse the audience.
  • Use contrast: light on dark or dark on light.
  • Graphics should make a key concept clearer.
  • Place your graphics in a similar location within each screen.
  • To temporarily clear the screen press W or B during the presentation. Press Enter to resume the presentation.


  • Font size must be large enough to be easily read. Size 28 to 34 with a bold font is recommended.
  • It is distracting if you use too wide a variety of fonts.
  • Overuse of text is a common mistake.
    • Too much text makes the slide unreadable. You may just as well show a blank slide. Stick to a few key words. 
    • If your audience is reading the slides they are not paying attention to you. If possible, make your point with graphics instead of text.
    • You can use Word Art, or a clip art image of a sign, to convey text in a more interesting way.


  • Numbers are usually confusing to the audience. Use as few as possible and allow extra time for the audience to do the math.
  • Numbers should never be ultra precise: 
    • “Anticipated Revenues of $660,101.83” looks silly. Are your numbers that accurate? Just say $660 thousand.
    • “The Break Even Point is 1048.17 units. Are you selling fractions of a unit?
    • Don’t show pennies. Cost per unit is about the only time you would need to show pennies.
  • If you have more than 12-15 numbers on a slide, that’s probably too many.
  • Using only one number per sentence helps the audience absorb the data.


  • Use the same scale for numbers on a slide. Don’t compare thousands to millions.
  • When using sales data, stick to a single market in the presentation. Worldwide sales, domestic sales, industry sales, company sales, divisional sales, or sales to a specific market segment are all different scales. They should not be mixed.
  • Cite your source on the same slide as the statistic, using a smaller size font.


  • Charts need to be clearly labeled. You can make more interesting charts by adding elements from the drawing toolbar.
  • Numbers in tables are both hard to see and to understand. There is usually a better way to present your numerical data than with columns and rows of numbers. Get creative!
  • PowerPoint deletes portions of charts and worksheets that are imported from Excel, keeping only the leftmost 5.5 inches. Plan ahead.


  • Backgrounds should never distract from the presentation.
  • Using the default white background is hard on the viewer’s eyes. You can easily add a design style or a color to the background.
  • Backgrounds that are light colored with dark text, or vice versa, look good. A dark background with white font reduces glare.
  • Colors appear lighter when projected. Pale colors often appear as white.
  • Consistent backgrounds add to a professional appearance.
  • For a long presentation, you may want to change background designs when shifting to a new topic.


  • Slides for business presentations should be dull! You don’t want to distract the audience.
  • Sounds and transition effects can be annoying. Use sparingly.
  • Animation effects can be interesting when used in moderation.
    • Too much animation is distracting.
    • Consider using animated clip art
    • Consider using custom animation
  • You can insert video and audio clips into PowerPoint.
  • You can also insert hyperlinks.

Hints for Efficient Practice:

Timing – Practicing Your Presentation,

  • Talk through your presentation to see how much time you use for each slide.
  • Set the automatic slide transition to the amount of time you want to spend discussing each slide.
  • Are you using the right amount of time per slide? Decide which slides or comments need alteration to make your presentation smoother.
  • Change the automatic slide transition settings for individual slides to fit the amount of time needed for that slide and practice again. Are you still within the time limit?
  • Decide if you want to remove the automatic slide transition feature before giving the presentation.


  • Make a list of key words/concepts for each slide
  • Read through the list before you begin.
  • Don’t attempt to memorize your text;
  • Your words will probably be different each time you practice.
  • Think about the ideas, and your words will follow naturally.

Delivering Your Talk:

Pre-Talk Preparation

  • Plan to get there a few minutes early to set up and test the equipment.
  • Dress appropriately for your audience.
  • Turn off your cell phone.


  • Edward Tufte, the leading expert on visual presentation techniques, advises speakers to always prepare a handout when giving a PowerPoint presentation.
  • Make about 10% more handouts than you expect to use.
  • Distribute handouts at the beginning of your talk.


  • Jump right in and get to the point.
  • Give your rehearsed opening statement; don’t improvise at the last moment.
  • Use the opening to catch the interest and attention of the audience.
  • Briefly state the problem or topic you will be discussing.
  • Briefly summarize your main theme for an idea or solution.


  • Talk at a natural, moderate rate of speech
  • Project your voice.
  • Speak clearly and distinctly.
  • Repeat critical information.
  • Pause briefly to give your audience time to digest the information on each new slide.
  • Don’t read the slides aloud. Your audience can read them far faster than you can talk.

Body Language

  • Keep your eyes on the audience
  • Use natural gestures.
  • Don’t turn your back to the audience.
  • Don’t hide behind the lectern.
  • Avoid looking at your notes. Only use them as reference points to keep you on track. Talk, don’t read.


  • Always leave time for a few questions at the end of the talk.
  • If you allow questions during the talk, the presentation time will be about 25% more than the practice time.
  • You can jump directly to a slide by typing its number or by right-clicking during the presentation and choosing from the slide titles.
  • Relax. If you’ve done the research you can easily answer most questions.
  • Some questions are too specific or personal. Politely refuse to answer. 
  • If you can’t answer a question, say so. Don’t apologize.  “I don’t have that information. I’ll try to find out for you.”


  • To end on time, you must PRACTICE!
  • When practicing, try to end early. You need to allow time for audience interruptions and questions.


  • Show some enthusiasm. Nobody wants to listen to a dull presentation. On the other hand, don’t overdo it. Nobody talks and gestures like a maniac in real life. How would you explain your ideas to a friend?
  • Involve your audience. Ask questions, make eye contact, use humor.
  • Don’t get distracted by audience noises or movements.
  • You’ll forget a minor point or two. Everybody does.
  • If you temporarily lose your train of thought you can gain time to recover by asking if the audience has any questions.


  • Close the sale.
  • Concisely summarize your key concepts and the main ideas of your presentation.
  • Resist the temptation to add a few last impromptu words.
  • End your talk with the summary statement or question you have prepared. What do you want them to do? What do you want them to remember?
  • Consider alternatives to “Questions?” for your closing slide. A summary of your key points, a cartoon, a team logo, or a company logo may be stronger.
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multimedia & communications technology

Basic multimedia communication technology tends to cover a range of multimedia devices, such as sound cards and graphic cards that allow users to create visual presentations that output sound and /or images. Multimedia generally means the combination of two or more continuous media. The two media are normally audio and video, sound plus moving pictures. For example the digital camera may be used externally to the PC, and allows the user to record images. When connecting the camera to the computer, using a cord, images will be formatted and printed. Various computers have sound cards stored within them, this allows output of sound from speakers through the use of CD’s, and other formats that may have music attached to it. Sound cards allow individuals to listen to music played or stored on their computer.

Whereas Communications technology refers to the transmission of data from one computer to another from one device to another. Computer systems refer to an entire working computer. All computer systems consist of various components they include the case of the computer the power supply and many other components.

The Motherboard in a computer that manages the communication function of all information. The Processor is another term for (CPU) Control Panel Unit. A microprocessor chip, the CPU is the brain of the computer; it uses mathematical functions to perform calculations.


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May 11, 2011

So I know that I dont have to blog for this week because we dont have class but I just wanted to say that I really enjoyed your class. I learned a lot from the presentations each week. This was probably my favorite class (and the easiest). I hope I make an A in this class! HAVE A GREAT SUMMER 🙂

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blog 2 for wednesday, may 4th

I really hope everyone enjoyed our presentation this past week. I had so much fun looking up inappropriate tweets. Just remember that there are right ways and wrong ways to use social networking sites. Some sites are meant to be positive and then go negative really quick. Pictures, posts and statuses can all contribute to this. If you think something on Facebook or Twitter is inappropriate and shouldnt be posted, be sure to report it. People need to watch what they do and say online for sure.

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blog 1 for wednesday, may 4th

When the first group presented, it scared me a bit when Seth said that nothing on the Internet was ever deleted. I guess I already knew that but his presentation was very informative and made me think about the stuff I put online a little more. I found an article online about privacy on the Internet. The article said to try this:

Take a photo and upload it to Facebook, then after a day or so, note what the URL to the picture is (the actual photo, not the page on which the photo resides), and then delete it. Come back a month later and see if the link works. Chances are: It will.

Facebook isn’t alone here. Researchers at Cambridge University (so you know this is legit, people!) have found that nearly half of the social networking sites don’t immediately delete pictures when a user requests they be removed. In general, photo-centric websites like Flickr were found to be better at quickly removing deleted photos upon request.

This was a really interesting article!

Here is the URL to it so you can read more if you like.


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free web presence

I looked at different sites that allowed me to make my own website such as Weebly  and Yola. They looked pretty simple enough to do. Here are some alternate reasons of why and why not someone should set up a website:

Reasons for setting up a website:

  • You want to communicate information or opinions to your customers, clients, organization members or friend.
  • You want more visibility for your business or organization.
  • You want to sell goods or services, or solicit donations.
  • You want to provide round-the-clock answers to questions about a product, a disease, a musical group, a passion, a hobby. You want to free up your service people for the hard questions.
  • You want to sign people up for a service or membership


Reasons for NOT setting up a website:

  • Are there better ways to communicate with your audience?Just because everyone seems to have a website these days, that doesn’t mean you need one too. If your business is purely local, you might better spend your time joining the Rotary Club or the Chamber of Commerce.
  • It takes time and energy to set up a website and keep it updated.You’ll have to gather the pictures you want to use for your website. You’ll have to plan the website and you’ll have to write the website page copy. Even if you were to hire a professional website designer, those are tasks you won’t be able to delegate.
  • Are there better ways to get visibility online?
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I personally do not like podcasts. I never listen to them for the fun of it. I cant concentrate when just listening to something, especially when it comes to schoolwork. I would rather be in class than have to listen to a podcast and take notes at home. If I ever come across to a podcast that sounds interesting, I may listen to it. Until then I plan on staying away from them lol.

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