Fall 1998 Computers and Society
Tuesdays 6 - 9:40 PM in 113 Rackham: GST 2710, Section 990 and AGS 3360, Section 983
Mondays 5:30 - 9:10 PM at NWAC: GST 2710, Section 984
Course web site: http://www.cll.wayne.edu/isp/drbowen/casf98/
Last updated: 10/27/98
Link back to course Welcome...

Eighth class: Agenda
Rackham: Tuesday October 27 / NWAC: Monday November 2

1. Announcements:
   1. The Midterm is next week, two hours allowed. Tuesday November 3 for Rackham, Monday November 9 for NWAC. After the Exam, time for Lab.
   2. Since people have trouble remembering the URL for the course web site, it will be at the top of every agenda from now on.
   3. On the course web site, there are supplementary materials. I have collected these under a "Supplementary materials" heading. These are not required for this course, but may help you to understand required concepts.
   4. Sign in on the course web site (every class).
   5. Other computers that you can use for the labs
      1. NOTE: Besides the Rackham and NWAC computer labs, other computers will not have the lab document files from the CD-ROM in the textbook, since those files are specific to this course. If you want to use these lab document files, you will need to them on your floppy disk. You cannot fit ALL of these files on your floppy disk at the same time. Just put on the one(s) you want to work on at that time. Also, make sure that you get all the questions possible answered beforehand, since generally the lab technicians will not know the specifics of this course.
      2. The NWAC lab is open much of the time. The Rackham lab hours are posted on the course web site.
      3. The Dell computers at the Adamany Undergraduate Library run WindowsNT with Office97.
      4. The computer labs at the other CLL Centers are set up like the NWAC computers -- WindowsNT and Office97. For a map of the CLL centers, go to the CLL web site at http://www.cll.wayne.edu/ and click on "off-campus sites". For local maps, hours and telephone numbers, click on the individual sites you are interested in.

      NOTE for Rackham: WindowsNT works almost exactly the same as Windows95. You will NOT have to switch back and forth between Mac and Windows in these labs.

   6. The people listed below still need to log on to the computer conference for this class. For instructions, see Agenda 5, VII.A.
      1. Rackham (Tuesdays)
         1. Melanie Brown
         2. Nantambu Kohlbatz
         3. Pamela Shaw
         4. William Swazer
      2. NWAC (Mondays)
         1. Joyceline Blackmon
         2. Jason DeMeyer
         3. Precious Sampson
         4. Jevon Woods
2. Handouts, pass backs
3. Logic Gates worksheet. Attached handout.
4. The Internet II: Applications. For background, recall that the Internet is a network for delivering packets of data between any two computers that are connected to the Internet. The Internet itself does not "know" or "care" what the content of the data packets is; the Internet is a transport mechanism for data packets. The content of the data packets depends on the Internet applications that are used.
   1. World Wide Web (the Web)
      1. For the Web, the user's client is also known as a Web Browser. Specific examples are Netscape Explorer and Communicator, and Microsoft Internet Explorer. The client request a document from a web server by sending a URL, or Universal Resource Locator, for example http://www.cll.wayne.edu/isp/drbowen/casf98/agenda_7.htm
         1. http:// -- the method. Tells what method is to be used to send the document. This stands for Hypertext Transport Protocol. In the field of computers, a protocol is an agreement about how computers will communicate. Hypertext is linked text -- text with links. Transport refers to moving information. http = an agreement about how computers (client and server in this case) will transport hypertext.
         2. www.cll.wayne.edu = domain name of the server computer. NOTE: the domain names for web servers do not have to start with www. A synonym for the CLL web server is fls.cll.wayne.edu. Also, the numerical IP address works; try 141.217.142.149.
         3. agenda_7.htm = requested file name. htm = Hyper Text Markup Language (HTML). In computers, a markup language is a set of codes for formatting text. So HTML is an agreed-on set of codes for formatting Hypertext.
         4. Everything between the domain name and the filename is folder information about where on the web server computer the desired file is located. The web server is configured with a "document root" directory, and the folder information in the URL is relative to that document root.
         5. If there is no filename in the URL, the web server sends a default file from the specified directory.
         6. Thus, the URL says what computer the desired information is located on, what folder it is in, and what is the name of the file. The web server sends this file back to the client.
         7. The sequence is thus client to server to client.
      2. The Web has been and is being upgraded rapidly. Currently there are enhancements for graphics, sound, video and "scriplets" to run programs on the client (Java is the prime example). Another enhancement is interactivity, in which the user submits information and gets back a customized response (for example, a report on grades).
      3. The Web is growing enormously rapidly. It is already what most people mean when they say they are "on the Internet" or that they "have the Internet". It is rapidly incorporating all of the other Internet functions, such as email. Within the next few years, it will most likely become possible for anyone who wants a web site (a server with a domain name) to host their own on their home computer. Web Sites are already offered by many ISPs and special-purpose web site hosting companies. A sizeable web site can be yours for $20 per month or less through one of the many web hosting services (companies). Some sites (www.geocities.com, for example) offer free web sites. These may add advertising and/or charge your users for access.
      4. A web client (a.k.a. web browser) is a computer with an Internet connection and running web client software. Similarly, a web server is a computer with an Internet connection and running web server software. If you dial in for your Internet connection, you get a different IP address each time you connect. Also, some computers with permanent connections get a different IP address each time they boot up. This is fine for a web browser, but for a web server, users have a very difficult time, and also the domain name system will not work without a fixed IP address, at least as it is presently set up. Therefore, web servers have fixed IP addresses. In the next few years, dial-up users may have fixed IP addresses, and if this happens, home computers will be able to host web sites on a practical basis.
      5. There are over 200 web browser programs, and 50 web server programs. Most of these interoperate seamlessly, but there are exceptions. If you plan on creating web content (if you are good, it pays very well nowadays), you will need to become familiar with the exceptions.
   2. Internet email. (Most LANs have an email function that is local, confined to that specific LAN. Internet email works between any two computers connected to the Internet.)
      1. An Internet email address has the form UserID@domain.name.domain, for example drbowen@cll.wayne.edu. The text to the right of @ is the domain name of a mail server computer and the text to the left is the name of an email account on that mail server. To send an email message, the user composes a message using email client software, and gives a "send" command, by typing a code or clicking a button. This send the message to the user's email server (the one that has her/his account). That server sends the message to the mail server in the "TO" address. The message is stored there until the intended recipient checks his/her email account, using email client software, at which time the email server sends the message to the recipient. The cycle is client 1 ==> server 1 ==> server 2 ==> client 2. (In contrast, the web cycle is client ==> server ==> (same) client.).
      2. Because email is such a low-level function (generally ASCII codes only, although this is changing), the many different email clients and email servers work interoperate almost seamlessly.
   3. Telnet
      1. Telnet is an Internet application in which one computer runs another one. The computer that is being run must have a command-line interface, similar to DOS, or must be capable of using a command-line interface. Windows computers can use a command-line interface in a DOS window. With a command-line interface, the computer puts a command prompt of some kind on the screen indicating that it is ready to accept a command from the user. The exact nature of the prompt depends on the operating system being used (DOS, Unix, etc.). For DOS, the command prompt is usually C:\>. The user types in a command and taps the <Enter> key. The computer executes the command. When the execution is complete, the computer puts the command prompt on the screen again, and waits for another command.
      2. To establish a Telnet session, a user with a Telnet client running on her/his computer must log in to a Telnet server over the Internet. After log in, keystrokes from the client are sent to the server. The server takes these keystrokes as if they came from its own keyboard and executes them. Any screen output is not displayed on the server's screen but is sent back to the client. The client displays the screens as if they were its own. In this way, after log in, it seems to the user with the Telnet client as if s/he were running the server computer.
      3. Obviously, Telnet allows for a great deal of mischief. It is one of the chief methods of hacking into other computers. Telnet users are usually restricted in the directories and commands they can use. On a Telnet server, only certain users may be accepted. Login, as usual, requires a UserID and a password. Since legitimate users have trouble remembering their passwords, passwords are often remarkably easy to guess.
5. Lab 7. Do Part 3, Lesson 2 (setting up an Excel spreadsheet).
   1. Loading the practice file. You should be aware by now that you may find the the practice files in places other than what the books says. I do not know how the files came to be in so many different places. The installation CD-ROM always puts them in the same place, as far as I can tell, and that is in a folder off of the root directory. Where can the lab files (Office 97 6 in 1 Step by Step) be?
      1. In "Favorites" folder (in the File Open dialog, this is a folder icon with asterisk on it). This seems to be pretty consistent at NWAC, although on one of the computers, someone had deleted all of these files.
      2. In a folder named c:\Office 97 6 in 1 Step by Step.  The files can be both here and in "Favorites."
      3. On the Windows 95 desktop (this is a level above the C: drive and even above the "My Computer" level).
   2. Since it is difficult to find the files in the File Open dialog, if you have been having trouble finding these files, it is probably best to use Windows Explorer (NWAC: Windows NT Explorer) to find them before starting Word. Do a Find for 02Lesson.doc. Bear in mind that the Excel and Access files will be in slightly different levels.
   3. When the book says to save your file, do not save it to the place they say, but to your floppy diskette. Save regularly. Make sure that your last save includes the changes in C below (that is, save after you make these changes, and the header will be included automatically).
   4. For this lab, do "One More Step" on pages 277 & 278, to add the graphic.
   5. Print out a copy of your spreadsheet at the end of  the regular part of the lesson, on Pg 259. Print out each worksheet separately and staple the sheets together. To put your name, Lab # and class section on the printouts,
      1. Choose the "Header and Footer..." item on the "View" menu
      2. Type in the information in the header
      3. Click OK

Assignment 8

Assignment 8 is to study for the Midterm.