Agenda 10

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: 11/10/98
Link back to course Welcome...

Tenth class: Agenda
Rackham: Tuesday November 10 / NWAC: Monday November 16

Announcements:
1. Tuesday, November 24. No class for Rackham Section.
2. Quiz 6: Monday November 30 (NWAC) / Tuesday December 1 (Rackham). You will be using the computers for this. Can you open a file from a floppy disk? Can you save a file to a floppy disk? Do you know how to insert a Header with your name on it in Word and Excel? Can you change fonts in Word? Can you left align, right align, justify and center a paragraph in word? Can you enter a formula in Excel?
3. Sign in on the course web site (every class).
4. The people listed below do not have on-line grade reports enabled. This is not a requirement for the course, but it does give you a good record of how you are doing. If you are on the list below, and want on-line grade reports, leave a note for me, including the password that you want to use to access grade reports.
  1. Rackham (Tuesdays)
    1. James Hobbs
    2. Frazier Kimpson
    3. Pamela Shaw
  2. NWAC (Mondays)
    1. Veronica Hill
    2. Gladys Karlin
    3. Melissa Mobley
5. 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
  2. NWAC (Mondays)
    1. Joyceline Blackmon
    2. Jason DeMeyer
    3. Precious Sampson
    4. Jevon Woods
6. Since people have trouble remembering the URL for the course web site, it will be at the top of every agenda from now on.
7. 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.
Handouts, pass backs
Comments on readings
1. "Last mile". This refers to the expense of installing high speed Internet wiring from the telephone switching station near your home, to your home. Because there are so many of these, the thinking was that installing fast wiring would be very expensive. Today it appears that the ordinary telephone wiring that already exists can be made to carry high data rates with enough microprocessor power at each end. This is a "digital signal processing" or DSP solution. The proposal is that, when you buy a DSP modem, it would stay connected all of the time, even if your phone was hung up, that you could talk on the phone and use the data connection at the same time, and that the connect charges would be a very small addition to your normal telephone bill. An alternative is to use cable TV wiring, that also already exists, and "cable modems." The Communication Act of 1996 opens the way for all of this, and the hope is that there will be a high degree of competition. So -- confusing choices, but lower bills and better service.
2. Hypertext Vs hypermedia. Hypermedia means linked media, just as Hypertext means linked text. Media adds sound and graphics (including video) to text.
3. Bitmap Vs Vector graphics, or Paint Vs Draw programs. Vector drawing programs describe objects, such as circles and squares, by giving their types, locations, sizes, line widths, line colors, etc. Vector graphics files store the information in this form. Vector graphics or "draw" programs can be more intelligent that bitmap programs. For example, you can select a circle and edit (change) it, for example by changing its location by dragging, by changing its size by dragging, etc. With bitmap programs, you cannot select objects, only bits. If there are overlapping objects, say a square and a circle, a bitmap program cannot separate them.
  
  On the other hand, most displays (monitor, printer) are bitmap devices, and the vector representaiton must be turned into a bitmap ("rendered" into a bitmap). also, in the end, bitmpa programs allow the highest quality editing by manipulating the bits individually. The expert computer-graphic artist must master both types of programs.
4. Left out - Project Management Programs (e.g. Microsoft Project Scheduler). For large projects involving many steps and large staffs, these can be invaluable for scheduling everything and keeping track of whether the project is ahead or behind of its schedule. It also prevents overallocating resources or underallocating them. For example, if Jane is busy during Month 1 doing planning, but is scheduled for two full-time jobs during Month 2 (say planning and budgeting) and seems to have Month 3 with nothing to do, the Project Scheduler will catch that so that the planner can fix the mistake.
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.
4. FTP (File Transport Protocol)
  1. This is the second-most common method in URLs. FTP is the Internet method for transferring files between computers.
  2. The client logs in to the server and can then get directories, change folders and transfer files in both directions.
  3. Transferring files across computer platforms, such as Mac to Windows, can be done for certain types of data files. Program files, of course, cannot be run on different programs. (Only high-level language files can be transferred, before they are compiled to machine language.)
    1. Text files are slightly different on Windows, Mac and Unix platforms. The difference is the "end of line" codes. Windwos uses CR-LF (ASCII 13 followed by ASCII 10). Mac uses only one of them, while Unix uses only the other. FTP will translate if the transfer method is set to "Test."
    2. More complex data files usually will not transfer across platforms. Word and Excel have been rewritten so that the files can be shared across platforms.
Databases Vs Spreadsheets
This week in the lab we start on databases. At first, it is easy to confuse a database and a spreadsheet. Both have columns and rows, for example. Here is the difference:
1. Spreadsheet. The layout of the spreadsheet is completely free-form. For an invoice, such as the ITC invoice, there may be a logical layout, but that is not imposed on you by the spreadsheet program. For example, you layed out the purchased items top to bottom, but as far as Excel is concerned, it would work just as well left to right or bottom to top (well, bottom to top might be a little less convenient to set up, but it would work.)
2. Database. Each row is a "record" and contains all of the information about a particular case. For example, in an employee database, each row or record could be a different employee, and would contain all of that employee's information. The types of information have to be the same from record to record. That is, "Last Name" would have to be in the same column, and would have to be text information, and would have to have the same maximum lenght. In a database, the columns are also called "fields." Each record has to have the same fields, in the same order.
3. Because the database records all have the same format, the computer only has to remember the structure of a single record. In a spreadsheet, however, any cell can do anything, and the computer has to allow for remembering this. Since this requires memeory, most spreadsheets have limits on the numbers of rows and columns, while most database programs have no limits on the number of records they can handle. database files a some of the largest files in the world.
4. Databases often contain "mission critical" information and so have special guards against failure. For example, if you make a change in a database field, that change is saved immediately, right when you make it. There is no waiting for Save or Save As.
Paper and Pencil Computer. See handouts.
Lab 9.
1. For the next class, have your WSU email AccessID and password with you.
2. In Microsoft Office Step By Step, do Part 5, Lesson 1 (Viewing, Entering and Customizing Data). this uses the Microsoft Access database program.
  1. Because Access saves all changes immediately, and will only save individual tables, not a whole database, use Windows Explorer (NWAC: Windows NT Explorer) to copy the database to your floppy diskette before you open it.
  2. On Pg 466, print out only the page of the Customers table that has your changes on it. This is the last page. Here are detailed directions for doing this. With the Customers table open,
    1. Choose the menu item File / Page Setup
    2. In the Page Setup dialog, click on the Page tab and then click on the Landscape radio button. click OK.
    3. At the bottom left of the Print Preview window, click on the "forward" button to advance to the last page. Remember the last page number. Close the Print Preview window.
    4. Choose the menu item Print... On the Print dialog, find the Pages From: text box and type in the number of the last page. That should ungrey the To: text bos; type the same number in there. Click OK.
  3. On Page 474, print out only the pages of the Bonbons table that have your changes on them. Use the technique in Item 2 directly above.
  4. Turn in your printouts for 2 and 3 above.

Assignment 10

For the next class, have your WSU email AccessID and password with you.
In Computers in Your Future 98, answer the following questions:

Pg 9-13, the 10 Completion questions.

Pg 9-28, the 10 Completion questions.

Pg 9-44, the 10 Completion questions.

Pg 9-62, the 10 Completion questions.