To Lecture Notes
IT 130 -- 1/13/09
Review Questions
- Why is it better to use transistors rather than vacuum tubes for building
electronic computers.
Ans: Because transistors are smaller, faster, and more reliable than vacuum tubes.
- Who invented HTML? Why was it invented?
Ans: It was invented by Tim Berners-Lee from the CERN particle accelerator
lab in Geneva, Switzerland and France. HTML was invented for displaying
scientific papers on the Internet.
- Why was Mosaic an important browser? Who invented it?
Ans: It was invented by Marc Andressen at the University of Illinois at
Champagne-Urbana.
- What are the rules for the name of an HTML file?
Ans: No embedded spaces, no uppercase letters.
- What are the rules that an XHTML document must satisfy?
Ans: See the 1/11 Lecture.
- Write an inline style for a size 1 heading that specifies
white Chiller font that is in bold, centered and twice as large
as normal, on a white background.
Ans:
<body style=font-family:Chiller; font-weight:bold;
text-align:center; font-size:200%;
background-color:black>
- Write an inline style to indent the first line of a
paragraph by 1 centimeter. Look up how to do this in the
Cascading Style Sheets
Reference
Ans: Use style=text-indent:0.5in;
where 0.5in is the distance to indent.
Units for Measuring Computer Information
- A bit is a single binary digit (0 or 1).
- A byte is 8 bits.
- A kilobyte (one K) is 210
= 1,024 bytes.
- A megabyte (one Meg) is 220
= 1,048,576 bytes.
- A gigabyte (one Gig) is 230
= 1,073,741,824 bytes.
- A terabyte is 240
= 1,099,511,647,776 bytes.
- A petabyte is 250
= 1.126 × 1015 bytes.
The Nonbreaking Space Symbol
- The ampersand (&) denotes
a special symbol in HTML/XHMTL.
- The nonbreaking space (HTML special symbol:
)
denotes a space that cannot be eliminated by a browser or broken
across lines of text.
- Repeated ordinary spaces between words are reduced to one
space by the browser.
- Use if you want more than
one space between two words.
- Other important HTML special symbols:
< (<)
> (>)
& (&)
" ()
- Here is a more complete list of
extended HTML characters.
File Permissions
- The permissions of posted web files and the folders that contain them
must be set correctly.
- To check or change the permission of files and folders, right click
on the file or folder on the server side of SSH and select Properties.
- The permissions for files and folders should be set correctly when
they are created with SSH. However, sometimes permissions get flipped
unexpectedly.
- Here are the recommended permission settings:
Read permission allows web files to be viewed by a browser and
allows folders to be accessed.
Read permission must be set for all groups (owner, group and other)
for folders and files.
Write permission allows web files or folders to be modified or deleted.
Write permission for files and folders should be set for the owner only,
not for group and other.
Execute permission allows the contents of a folder to be displayed.
Execute permission should be set for all groups for folders.
Execute permission should not be set for files.
Images
- Use the following tag to place the image myimage.jpg
on your webpage:
- Place this tag where you want the image to appear on
the page.
- The source image (src) is myimage.jpg.
- An img tag is a combination start/end tag.
Hyperlinks
- A hyperlink is text on a webpage that, when clicked,
causes the browser to display a different page or image.
- Add this tag to display a hyperlink on your page:
<p><a href=http://www.disney.com target=new>
I want to go to Disneyland</a></p>
- The hyperlink text is I want to go to Disneyland.
- You change the href address and hyperlink text to show your favorite
website.
- In the hyperlink tag, a means address, href means
hyperlink reference and target=new means open the page
in a new browser window.
Tables
- Use the delimitors
<table> and
</table>
for the rows of a table.
- Use the delimitors
<tr> and
</tr>
for the items in a particular row of a table.
- Use the delimitors
<td> and
</td>
for the contents of an item within a row of a table.
<td> means table definition.
- See the Tables Example.
Right click on the document and select View Source to see the
source code.
Project Proj3