Tony Lembke
The Help Desk
Computing Columns
Clinical Computing
Lecture Notes
Introduction to the Internet
Part 1 : What is the Internet?
The Internet is an international network of computers. It consists of the computers themselves, the cables that connect them, the information they contain and the people who use them.How does it all work?
The Internet is analogous to the telephone system, but is quite distinct from it.
The telephone system in Australia consists of a number of regional exchanges, connected by large telephone cables. The Australian system is connected by underwater cable to the American and Asian systems, and thence to the rest of the world. Individual users have a private phone that is connected by cable to the nearest exchange, and thereby to the overall system.
The Internet also consists of a number of regional exchanges, which are large computers called servers . These servers are connected by a large cable (of copper wire), which is quite separate to the telephone system. Undersea cables connect the Australian system to the American system, and thence to the rest of the world. Universities and government departments own these servers, and are thus able to pass information back and forth. They are thus permanently connected to the Internet.
Recently, private companies called Internet Service Providers (ISPs) have established servers on the Internet cable. Individual users from their home or office connect to the server of an ISP, and thereby gain access to the entire Internet system. This connection between a user and their ISP is made over a normal telephone line. The ISP has a number of incoming lines to their office (like an SP bookie), which enable a number of users to connect to their server. 'Server ' & 'ISP s' are terms used frequently in these notes.
Individual users must therefore dial a number over the normal telephone system to connect to their ISP. This is called 'logging in'.
Who owns the Internet?
No one, and everyone. The Internet in Australia was established by the universities to facilitate communication and research, and thus was funded by the federal government. It was managed by a subsidiary of the Universities until last year, when Telstra took over the upkeep of the cables. It belongs to everyone in the same way as the roads and the telephone system.
How many people are connected?
The number of people connected to the Internet is said to double every 55 days, so any figure quoted is guesswork. It numbers now in the many millions.What do I need to connect?
You need a computer and a modem, and an arrangement with an Internet Service Provider (ISP).
What sort of computer do I need?
One of the features of the Internet is that its operation is independent of the computer you are using, in the same way as you can use any brand of telephone to connect to the telephone system.
Many of those connected to the Internet use Apple Macintosh. Any PowerPC would be suitable. Most of the rest use IBM Compatible PCs, and a Pentium or later model would be fine. Unix computers are also suitable. (Some hand held computers also can connect to the Internet).
What is a Modem?
A modem is simply a device that plugs into your computer at one end and into a normal phone socket at the other. It converts the information from your computer into sound, and sound coming down the phone line back into information. There are a number of brands available. It is sensible to buy the fastest model available, which currently is '56 baud'.
How do I find an ISP?
There are now hundreds of Internet Service Providers in Australia. The largest is Ozemail, but there are many others. You need an ISP that you can access with a local phone call, if possible. Then you can log on for just the price of a local call for an unlimited time. An ISP should also provide you with support in establishing your Internet access and be available to answer your questions. It is often not straight forward to get connected initially and is usually quite frustrating.
What about Software?
Interestingly, most of the software required for connecting to the Internet is provided free by its developers. Windows 98 and Apple System 8.5 come complete with much of the software required, and the rest is available from ISPs or comes attached to computer magazines or books.
What does it cost?
In fact, using the Internet is free, as it belongs to no one. If you owned your own server, there would be no charge. However -
ISPs recoup their investment in setting up and purchasing a server and in providing support by charging a fee to their users. There is often an initial establishment cost of about $100, and then a cost of about $4 an hour for connected time. This cost varies from ISP to ISP.
Can people then access my computer?
Your computer is separated from the Internet by the phone line to your ISP. Other people (including your ISP) can not gain access to the information on your computer.
Part 2 : What's out there when I getthere?
What is available on the Internet?
As discussed, the Internet is just a lot of computers connected by cable.
The attraction of the Internet is the people behind the computers and the information available on those computers.
We have become accustomed to the telephone system being able to transmit data in different forms - data can be transmitted as speech which is intelligible if one has a phone connected, and data can be transmitted as a fax which can only be understood by fax machines.
Data on the Internet can also be transmitted in different forms. The most common of these are as electronic mail, or email, and as a page of the World Wide Web.
Email is the 'killer app' of the Internet. It is the application that has the most impact in influencing the way people work
At the time we were first connected to the Internet, our Labrador had just had puppies. We received all sorts of conflicting advice as to how we should care for them, and were quite confused. We could not find a good reference book. My wife suggested we try the Net.
Using the World Wide Web, we found a page devoted to Labradors. A veterinary surgeon in Minnesota called Cindy had provided a great deal of information about their genetics, their whelping and the care of newborns. We sent a letter to her email address thanking her for the page and asking some further questions. That was at 11pm, and when we woke up she had replied in great length and with great enthusiasm. She suggested we join a 'mailing list' about Labradors, and so we sent a request for information to that list. That night we had more than 30 replies from all around the world lending us support and offering helpful advice. The power of email was quite extraordinary.
The local division of GP now uses email for all our communication. Articles can be passed for comments and editing and returned within hours, and issues can be discussed and decisions made by a number of people quickly and conveniently, each dealing with the mail at their own time and convenience.
Eudora - Mail Program
How does email work
When you register with an ISP, you are provided with an email address. The ISP establishes a 'mailbox' on his server uniquely identified by your address.My address is tlembke@om.com.au . The part of the address after @ is the address of my ISP, whose name is "om". The"com" part of the name indicates that this is a commercial ISP. Other suffixes are "edu", for universities, "gov", for government departments, "org" for organisations and "net" for networks. The "au" suffix indicates that this ISP is based in Australia. ISPs based in the USA have no suffix indicating their origin, in the same way that the UK do not put "UK" on their stamps.
I chose tlembke (my initial and surname) as a code. My ISP accepted this choice, as he had no other tlembke's subscribed. I could have chosen "bignose@om.com.au" or "winger@om.com.au" if I wanted.
People who want to send me an email message type "tlembke@om.com.au" as the address in their email software on their computer, and then tell their computer to "send messages". This message is sent to their ISP's server, and from there is directed from computer to computer in the network until it finds the server "om.com.au". That server places the message into the mailbox "tlembke". The message sits there until I connect to the server and send the command "Check Mail", at which time it is loaded down the phone line into my computer for reading.
It is considered good etiquette to reply to an email message within 24 hours.
What is email software?
There are a number of programs that one can use to manage email, and to send the commands "Check Mail" and "Send Messages". The most popular program is Eudora, which is available free for Macs & PCs.The World Wide Web
The World Wide Web (WWW) is a new Internet format, in that it has been in widespread use for less than 5 years, but is now the dominant means of providing information.
The WWW consists of a number (millions) of pages of information. These pages are displayed by a program on the user's computer called a web browser . These pages can consist of text, pictures, sound and movies. The pages on the Web connect to each other by the use of Links. When reading a WWW page, some of the words will be differentiated from others by being coloured or by being underlined. Pointing at such words and clicking the mouse will load another 'linked' page into the browser. This page may be on the same server, or may be on a computer on the other side of the world. Distance makes no difference on the Internet.
Where do these pages come from?
Pages for the WWW are available for display by being placed on a server computer. They are available from there to anyone connected to the Internet, anywhere in the world. There is a standard format for presenting this information (called HTML ) that makes it legible to any web browser. Each page has a unique address on the WWW, called a URL (Universal Resource Location).
eg. www.medicineau.net.au/computing/home.html
The prefix www.medicineau.net.au is the address of the MedAu server on the WWW, the various components of this address being the same as described in Email.
:computing" is the name of a folder (or directory) on the 'om' server, and home.html is the name of a particuler page within that folder.
What is a Web Browser?
A Web Browser is a program to read pages formatted for the WWW , and display them correctly on your computer. The most popular browsers are Netscape Navigator and Internet Explorer, which are available free for Macintosh and PC Computers.
Netscape navigator - A web browser
How much does information on the WWW cost?
Almost all information on the WWW is free of cost. A number of companies have tried to charge for services, but there is so much freely available that they were unsuccessful. Many information providers earn money by selling advertising space on their pages in the same way that commercial televisions stations make money from advertisers rather than viewers.What Information is available?
There is information on the WWW on almost any imaginable topic. Much of this is provided by interested aficionados and hobbyists, much by academics and students, and increasingly a large amount is provided by commercial interests. Also, established newspapers and magazines (ranging from the Sydney Morning Herald to Playboy) make most of their content available.
How do I find the Information I want?
A number of organisations attempt to catalogue the WWW.Yahoohas a database of web pages organised by topics and keywords (like Medline). Type in the topic you want and it presents you with a number of possible sites.
Alta Vista has a computer that spends all day reading web pages, and following the links on them. It catalogues every piece of text and graphic it comes across. You can search this database amazingly quickly considering the billions of pieces of information it contains.
Part 3 Northern Rivers Medicine & the Internet
Distance is not a handicap on the Internet, and the medical community in the Northern Rivers is ideally suited to take advantage of this new technology. We are a well defined and contained network, and by taking a lead in establishing a local Information Technology system we can benefit our patients, facilitate continuing medicinal education, make our clinical activity more efficient and provide an example for other regions.
Electronic transfer of information between doctors, pathologists, radiology providers and hospitals has the potential to facilitate better patient care, avoid unnecessary duplication of investigations and resources, and improve communication between GPs, specialists and hospitals.
There is currently a window of opportunity in which to establish a presence
on the World Wide Web.
The local division of General Practice has established a journal of Medicine
on the Web (Medicine Australia) which is currently the number one source
of Australian medical content. It includes articles of clinical interest,
literature reviews, information on computers in medical practice, and magazine
articles on Personal Finance, Legal angles, and stories and jokes for doctors.
It is a wonderful opportunity for those with a special interest , specific
talent or general enthusiasm to become involved in what has the early lead
in becoming the primary source of information for all Australian doctors.
When publishing on the Web, all readers can immediately become contributors,
which makes for a responsive, up to date and interesting journal. We would
welcome your participation.
Tony Lembke
tlembke@om.com.au
61 Main St
Alstonville 2477
(066) 280505
July 1996
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