Freshman Computer Notes

By: Ari Gilder

 

Remember, I can't cover everything in here, but I will do as much as I can. If you have any questions that aren't answered here, feel free to ask me.

 

I. Parts of a Computer

All the physical parts that make a computer function are called hardware. Programs and operating systems are called software.

Hardware

There are two kinds of hardware:  hardware in the computer, and stuff outside of it that provide input and output functions, or peripherals.

A. Hardware inside the computer case

1. The CPU or the Central Processing Unit. This is sort of like the 'brain' of the computer. It's what processes everything that you tell it to. The CPU is located on the motherboard. The speed of a CPU is usually measured in megahertz (MHz), but recently AMD has come out with a one-gigahertz processor (GHz).

2. The Motherboard is a large electronic board with many circuits and jumpers. All the hardware that you have in your computer has to connect to it in some way. The CPU is located on it, and there are slots for the RAM as well.

3. RAM stands for Random Access Memory. Sometimes it is also called temporary storage. This is because whenever you open a program, it is moved into the RAM, and when you close it, it disappears from it, making room for new programs to be opened. If you run out of RAM, your computer may give you an error that you have run out of memory. RAM is usually volatile, which means that when you shut off your computer, all the programs you have in RAM disappear. That is why it is good to save often. RAM is often called main memory or primary storage.

4. ROM stands for Read-Only Memory. This is usually found on CDs (hence the name CD-ROM). Until a year or two ago, CDs could only be read from. However, when the CD-R and CD-RW were invented, CDs could now be written (CD-R) and rewritten (CD-RW) to.

5. A Floppy Drive is a disk drive that can hold 3" floppy disks. Floppy disks are sometimes called auxiliary storage. They usually hold up to 1.44 MB of data. Floppy disks can be write-protected (not allowed you to overwrite on them) by moving the little switch-like thingy on the back in the top left corner, so that the hole is exposed.

6. The Hard Drive is what you store all your programs on when you aren't using them. While RAM is usually measured in megabytes, hard drive space is usually measured in gigabytes. Hard drives are also called auxiliary storage. Unlike memory, auxiliary storage is permanent until you delete it. A computer can have more than one hard disks.

7. A Zip Drive is also auxiliary storage, and is a lot like the floppy drive, except the disks used are a bit bigger. Zip disks can usually store either 100 or 250 MB. Zip disks are good for making backups of several folders. Zip drives may be internal or external.

8. A Tape Drive is basically the same thing as a zip drive, except it is used on a large-scale basis. Tapes can contain up to several gigabytes of information, and are very good for backing up your entire hard drive.

9. A Modem stands for modulator-demodulator. Modems are used to send data over phone lines. Now, there are very fast kinds of ways of doing this, such as DSL (Digital Subscriber Line), Cable Modems (don't use a phone line, directly connected to a cable company), or T1 (industrial-size modem, very fast). Modems can be internal or external.

10. A Video Card is what lets you see things displayed on the monitor. Many new video cards now support 3D graphics in games and such.

11. A Sound Card is what it sounds like- it lets you hear sound. The speakers connect to the sound card.

B. Peripherals and Input/Output devices

1. The Keyboard is the most common type of input device. It lets the user enter data by the use of keys. There are several types of keys on the keyboard. There are alphabetic keys, number keys (those above the alphabetic keys), arrow keys, function keys which can sometimes be programmed to do special tasks, predefined function keys (home, end, page up & down, caps lock, etc.), and the number pad which alternates between numbers and certain predefined functions (home, end, page up, page down, delete, and insert). Also, the Shift, Control, and Alt keys can be used to interact with a program from the keyboard when pressed with numbers or letters.

2. The Mouse is the most common type of pointer device. The mouse is an input device, and by moving it on a flat surface, you can control where the cursor of your mouse moves on your computer. The mouse usually has two or three buttons. The left button is the most commonly used, and it can be double-clicked to open a program, or single clicked to go to a link on a website or activate buttons, etc. The right button usually brings up a menu of certain things you can do in a program (such as undo, cut, copy, paste, and select all). Mice come also in three other variations: the trackball, where you roll a ball around in its socket to move the cursor, the touchpad, where you use your finger to control where the mouse goes, and the mini-joystick, which is common only in laptops, where you can move the cursor according to the movement of the joystick.

3. Joysticks are also input devices and are sometimes used to move cursors, but most often joysticks are only used in games and flight simulators. Joysticks usually have at least one or two buttons, but can have many others as well. These buttons can be programmed to do certain tasks sometimes.

4. Scanners are input devices that can take an image or a picture that you have and scan it into the computer for usage.

5. Microphones are just like what they are when used in assemblies and such. They simply let you talk into them and record your voice. With use of certain programs or websites, you can talk to people through voice online.

6. The Monitor is the screen that lets you see what's going on in your computer. The monitor is sometimes called a CRT or cathode ray tube. A monitor works by an electron gun producing different images when the electrons hit a screen of phosphor. The monitor can be adjusted in brightness, hue, contrast, and screen size. The latest technology is new flat-screen monitors that conserve a lot of space. Monitor size is measured in inches diagonally, from corner to corner. The screen size (the stuff that your computer produces and outputs) is measured in DPI or Dots Per Inch.

7. The Printer is an output device that lets you print text or graphics onto a piece of paper. Printers can either be standard printers, thermal printers which are a bit faster, and laser printers, which are faster also. Printers can either be just black-and-white or color. Something that is printed from the printer is called a hard copy.

8. Speakers are the output device that let you hear sound your computer produces. Speakers are attached to the sound card with the microphone.

 

Software

A. Operating Systems

An operating system is the master program that lets you run all your other applications and programs. Operating Systems (OS) usually let you multitask; that is, they usually let you run more than one program at once. Commonly known operating systems are: Windows 95/98/2000/NT, Linux, and DOS. Windows and Linux are the two more popular OS's that provide graphical user interfaces or GUIs.

B. Programs

1. Basic Structure of Programs

Programs are specialized applications that let you do specific things. Many programs though, have a similar structure. Most programs contain menus, where you can select options from. The top blue bar is called the title bar, because it contains the title of the program. Also, in the top right corner of the title bar, there is oftenly three buttons (although there are times there are only two or one). The first button, which looks like a '_' is the minimize button. When pressed, the program you see will disappear from view and shrink into the taskbar (the bottom bar) with its own little button. If you click that button, the program will come up again, usually in the state you left it. The second button is either a single box, or two boxes. If it is a single box, it is the maximize button. When clicked, it will make the program the size of the full screen. If there are two boxes, it is the restore button, which will shrink the program back to the size you had it before you hit the maximize button. The final button is the famous 'X'. When it is clicked, the program will terminate and exit.

2. Common Every-day Programs

a. Microsoft Word is a word processing application. It lets you type in text, format the text, and control the alignment of it. It also lets you insert pictures and clipart. Newer versions of Microsoft Word allow you to make web pages as well. A similar program to Microsoft Word is WordPerfect.

b. Microsoft Excel is an application that allows you to create spreadsheets. Spreadsheets are sort of like charts, but they allow you to perform mathematical calculations. Excel also has a feature of converting data you input into it into a graph.

c. Microsoft Publisher, PowerPoint, and Works are programs that allow you to create different kinds of projects, such as banners, signs, newsletters, or stickers.

d. Microsoft Access is a program that allows you to create databases. Databases are used for storage of information, such as the names, addresses, phone numbers and birthdates of your friends. Even though spreadsheets can accomplish this, databases are much more efficient.

e. Visual Basic is a program that allows you to create your own programs that accomplish certain tasks that you tell it to do. Visual Basic is also a programming language, like C++.

f. Visual Page is an application that lets you design web pages graphically instead of typing in the HTML code that creates web pages manually. Microsoft FrontPage also does the same thing as Visual Page.

g. Internet Explorer and Netscape are the most popular web browsers. Web browsers will be discussed more in the Internet section.

3. Windows Standard Features

a. Windows Explorer is a program inside Windows that lets you look through your files and directories in an organized fashion.

b. The Clipboard is a useful tool when transferring data. You can copy text, images, files, even entire folders or drives to the clipboard by hitting Ctrl+C (or Ctrl+X to cut). To paste the contents of the clipboard, hit Ctrl+V. Some programs, such as Microsoft Word 2000, support multiple things on the clipboard.

c. The Taskbar, Start Button and System Tray are generally at the bottom of the Windows screen, but it can be moved to the sides or the top. The taskbar displays all the programs you have running currently. The start button, when pressed, brings up a menu from which you can launch your programs, edit the system configuration, find files, etc. The system tray is the little indented part of the taskbar, on the right side, which contains the time and some other little icons.

 

Files

A. Common File Extensions

1. Text Files

a. .doc is the extension of a Microsoft Word document.

b. .wpd is the extension of a WordPerfect document.

c. .txt is the extension of Notepad and Wordpad text files.

d. .rtf is rich text format files, which allow bold, italics, etc. They are used commonly in Wordpad.

2. Image Files

a. .bmp stands for bitmap and is most commonly found in Paint.

b. .gif stands for graphics interchange file, and is on of the most common graphic files.

c. .jpg is the other most common graphics file, and is commonly used for pictures taken by digital camera or scanned in.

3. System Files

a. .dll is a dynamic linked library and are essential to the system. They contain functions that allow Windows and other programs to work properly.

b. .sys are files essential to the Windows system. Without them, Windows will not function properly.

c. .ini are configuration files. They can sometimes be edited to optimize Windows or programs for your needs, but be careful.

B. File Protection

1. Read Protect ensures that users cannot view the file.

2. Write Protect allows users to open and read the file, but not modify its contents.

3. R/W Protect or Read/Write Protect ensures that users cannot read or write to this file. This is best used on important documents or system files.

 

The Internet

A. Basics of the Internet

The Internet is a massive network, or computers connected through cables or phone lines (usually connected to a main computer called the server), of users sharing their data to the public. An intranet is a similar thing, except it is a private network between all the computers sharing data. Anyways, the Internet is also known as the WWW or World Wide Web. The Internet is accessed through ISPs or Internet Service Providers. Popular ISPs include AOL, CompuServe, AT&T, NetZero (a free ISP), and MSN. The Internet and most Intranets usually require you to log in with a user name and a password. The best choice for passwords are random letters and numbers, as they are they hardest to find out.

The Internet is composed of web sites which allow you to view all the data being shared on the Internet. Web sites are written in HTML, or hypertext markup language. They are viewed by browsers such as AOL, Internet Explorer, and Netscape. These browsers access the websites through HTTP or hypertext transfer protocol. Web sites can contain references to other web sites. These references are known as hyperlinks. Web sites are identified by their address, or URL (Universal Resource Locator).

Communication over the Internet can be achieved through e-mail or electronic mail. Unlike normal post-office snail mail (that's what its called, really!), you will get the message within approximately five minutes of it being sent to you. You can attach files to your e-mail and send them along with it to the recipient.  

B. Interacting with the Internet

The Internet provides certain tools to optimize your Internet experience, such as search engines. Search engines do what they sound like; they search the Internet for the keywords you type in. There are many, many search engines all over the internet. Some of the most popular are Yahoo, AltaVista, GoTo, HotBot, Lycos, Ask Jeeves, WebCrawler, MetaCrawler, and Google.

When using the Internet, it's sort of like a two way street. While you receive information, you can also send information. Receiving information from the Internet is called downloading. Sending information is known as uploading. Many things can be downloaded from the internet. Popular download sites include Download.com, Tucows.com, and Shareware.com. Shareware are programs that allow you to use the program (sometimes with certain features restricted) for a certain amount of time, and then you will be asked to register or buy the program. Freeware however, is software that is distributed for free, with no expiration or evaluation period.

 

Computer Measurements

A. File Sizes

1. Bits are short for binary digits. They are single values that can be either 0 or 1. Complex strings of these 0s and 1s are what tell the CPU what to do.

2. Bytes are strings of 8 bits. They are the basic unit in which memory is measured.

3. Kilobytes are 1024 bytes, but are often approximated to 1000.

4. Megabytes are 1,048,576 bytes, approximated to 1,000,000.

5. Gigabytes are 1,073,741,824 bytes, approximated to 1,000,000,000.

6. Terabytes are 1,099,511,627,776 bytes, approximated to one trillion.

B. Processor Speeds

CPU speeds are measure in hertz (Hz). Computers nowadays have processor speeds of several hundred megahertz (MHz) or now one gigahertz (GHz).

 

Miscellaneous Terms

A. An Icon is a small picture that represents a program, file, or folder. When double clicked, it will usually launch the program associated with it.

B. A Hacker is a person who uses special programs to manipulate other people's computers. By some definitions (although not very accurate ones), a hacker is someone who is 'very interested in computers'.

C. A Virus is a program that is created to cause damage to the user's computer. Hackers send viruses commonly, so it is worthwhile to be careful with what you download.

D. OCR stands for Object-Character Recognition or Reading. OCR is used when you scan in a text document with your scanner, you can change the image that you scanned in into words for use in word processors, etc.

 

That should be just about it, I tried to cover as many terms as possible that are on the website. If you have any more questions, feel free to ask me.

 

Copyright 2000 to Ari Gilder