What is a Firewall?
A firewall is a tool that monitors communication to and from your computer. It sits between your computer and the rest of the network, and according to some criteria, it decides which communication to allow, and which communication to block. It may also use some other criteria to decide about which communication or communication request to report to you (either by adding the information to a log file that you may browse whenever you wish, or in an alert message on the screen), and what not to report.
What Is It Good For?
Identifying and blocking remote access Trojans. Perhaps the most common way to break into a home computer and gain control, is by using a remote access Trojan (RAT). (sometimes it is called "backdoor Trojan" or "backdoor program". Many people simply call it a "Trojan horse" although the term "Trojan horse" is much more generic). A Trojan horse, is a program that claims to do something really innocent, but in fact does something much less innocent. This goes to the days where the Greek soldiers succeeded to enter through the gates of Troy by building a big wooden horse, and giving it as a present to the king of Troy. The soldiers allowed the sculpture to enter through their gates, and then at night, when the soldiers were busy guarding against an outside attack, many Greek soldiers who were hiding inside the horse went out and attacked Troy from the inside. This story, which may or may not be true, is an example of something which looks like something innocent and is used for some less innocent purpose. The same thing happens in computers. You may sometimes get some program, via ICQ, or via Usenet, or via IRC, and believe this program to be something good, while in fact running it will do something less nice to your computer. Such programs are called Trojan horses. It is accepted to say that the difference between a Trojan horse and a virus, is that a virus has the ability to self-replicate and to distribute itself, while a Trojan horse lacks this ability. A special type of Trojan horses, is RATs (Remote Access Trojans, some say "remote admin Trojans"). These Trojans once executed in the victim's computer, start to listen to incoming communication from a remote matching program that the attacker uses. When they get instructions from the remote program, they act accordingly, and thus let the user of the remote program to execute commands on the victim's computer. To name a few famous RATs, the most common are Netbus, Back-Orifice, and SubSeven (which is also known as Backdoor-G). In order for the attacker to use this method, your computer must first be infected by a RAT.
Prevention of infections by RATs is no different than prevention of infection by viruses. Antivirus programs can identify and remove most of the more common RATs. Personal firewalls can identify and block remote communication efforts to the more common RATs and by thus blocking the attacker, and identifying the RAT.
Blocking/Identifying Other Types of Trojans and WQorms?
There are many other types of Trojan horses which may try to communicate with the outside from your computer. Whether they are e-mail worms trying to distribute themselves using their own SMTP engine, or they might be password stealers, or anything else. Many of them can be identified and blocked by a personal firewall.
Identifying/Blocking Spyware's/Adbots?
Identifying/Blocking Spyware's/Adbots?
The term "spyware" is a slang which is not well defined. It is commonly used mainly for various adware (and adware is a program that is supported by presenting advertisements to the user), and that during their installation process, they install an independent program which we shall call "adbot". The adbot runs independently even if the hosting adware is not running, and it maintains the advertisements, downloads them from the remote server, and provides information to the remote server. The adbot is usually hidden. There are many companies that offer adbots, and advertisements services to adware. The information that the adbots deliver to their servers from the
Blocking Advertisements? computer where the adbot is installed, is "how much time each advertisement is shown, which was the hosting adware, and whether the user clicked on the advertisement. This is important so that the advertisements server will be able to know how much money to get from each of the advertised companies, and how much from it to deliver to each of the adware maintainers. Some of the adbots also collect other information in order to better choose the advertisements to the users. The term "spyware" is more generic, but most of the spyware fall into this category. Many types of adbots can be identified and blocked by personal firewalls.
Some of the better personal firewalls can be set to block communication with specific sites. This can be used in order to prevent downloading of advertisements in web pages, and thus to accelerate the download process of the web sites. This is not a very common use of a personal firewall, though.
Preventing Communication to Tracking Sites?
Some web pages contain references to tracking sites. e.g. instruct the web browser to download a small picture (sometimes invisible) from tracking sites. Sometimes, the pictures are visible and provide some statistics about the site. Those tracking sites will try to save a small text either as a small file in a special directory, or as a line in a special file (depending on what is your browser), and your browser will usually allow the saving site to read the text that it saved on your computer. This is called "web cookies" or sometimes simply "cookies". Cookies allow a web site to keep information that it saved some time when you entered it, to be read whenever you enter the site again. This allow the web site to customize itself for you, and to keep track on everything that you did on that site. It does not have to keep that information on your computer. All it has to save on your computer is a unique identifying number, and then it can keep in the server's side information regarding what has been done by the browser that used that cookie. Yet, by this method, a web site can get only information regarding your visits in it. Some sites such as "doubleclick" or "hitbox" can collect information from various affiliated sites, by putting a small reference in the affiliated pages to some picture on their servers. When you enter one of the affiliated web pages, your browser will communicate with the tracking site, and this will allow the tracking site to put or to read a cookie that identifies your computer uniquely, and it can also know what was the web page that referred to it, and any other information that the affiliated web site wanted to deliver to the tracking site. This way tracking sites can correlate information from many affiliated sites, to build information that for example will allow them to better customize the advertisements that are put on those sites when you browse them.
Some personal firewalls can be set to block communication to tracking sites. It is not a common use of a personal firewall, though, and a personal firewall is not the best tool for that, but if you already have one, this is yet another possible use of it.
Blocking or Limiting the NetBIOS Communication? (as well as other default services)
The two common methods of intruders to break into home computers, are through a RAT (which was discussed in II.3a) and through the NetBIOS communication. The NetBIOS is a standard for naming computers in small networks, developed long ago by IBM and Microsoft. There are a few communication standards which are used in relation to the NetBIOS. The ones that are relevant for Microsoft Windows operating systems, are: NBT (NetBIOS over TCP/IP), IPX/SPX, and NetBEUI. The communication standard which is used over the Internet, is NBT. If it is enabled, and there is no firewall or something else in the middle, it means that your computer is listening for communications over the Internet via this standard, and will react according to the different NBT commands that it gets from the remote programs. It is thus that the NBT (which sometimes loosely called "NetBIOS") is acting as a server. So the next question should be "what remote NBT commands the NBT server will do on the local computer". The answer to this question depends on the specific setting on your computer. You may set your computer to allow file and print sharing. If also NBT is enabled, it means that you allow remote users to share your files or printers. This is a big problem. It is true that in principle the remote user has to know your password for that computer, but many users do not set a password for their user on Windows, or set a trivial password. Older versions of Win95 had file and print sharing over NetBIOS enabled by default. On Win98, and WinMe it was disabled by default, but many technicians, when they set a home network, they enable the file and print sharing, without being aware that it influences also the authorizations of a remote Internet user. There are even worms and viruses who use the File sharing option to spread in the Internet. Anyway, no matter whether you need it for some reason or just are not aware of it, a personal firewall can identify and block any external effort to communicate with the NetBIOS server on your computer. The more flexible personal firewalls can be set to restrict the authorization to communicate with the NetBIOS. Some Windows operating systems, especially those which are not meant for home uses, offer other public services by default, such as RPC. A firewall can identify communication efforts to them, and block them. Since such services listen to remote communications, there is a potential risk when there are efforts to exploit security holes in the programs that offer the services, if there are such security holes. A firewall may block or limit the communication to those services.
to be contineu.....
Sunday, October 24, 2010
Tuesday, October 19, 2010
BIN & .CUE simple tutorial.
BIN & .CUE simple tutorial.
There always seems to be the question "what do I do with a .bin and .cue file" in these forums so I figured I would write a quick and simple tutorial. Please feel free to add more.
So you have downloaded two files, one with a .bin extension and one with a .cue extension. "What do I do with these?" you ask. There are a number of options.
BURN TO CD
You will need either NERO, CDRWIN or FIREBURNER to burn the file.
To burn with NERO:
Start NERO, choose FILE, choose BURN IMAGE, locate the .cue file you have and double click it. A dialog box will come up, for anything other than music make sure you choose DISC-AT-ONCE (DAO). You can also turn off the simulation burn if you so choose.
Then burn away.
To burn with CDRWin:
Start CDRWin, choose the button on the top left, choose LOAD CUESHEET, press START RECORDING.
To burn with Fireburner:
Start Fireburner, click on the button on the bottom left corner "VISUAL CUE BURNER/BINCHUNKER", press the right mouse button and choose LOAD TRACKS FROM .CUE and choose the correct .CUE file, press the right mouse button again and chooseselect "Burn/Test Burn", choose DISK AT ONCE (DAO), disable TEST BURN and MULTISESSION, press OK.
.CUE ERRORS
The most common error you will get with a .cue file is when it points to an incorrect path. This is easily fixed. Find the .bin file, copy the exact title including the .bin extension. Now find the .cue file, open the .cue file using notepad. It should look similar to this:
FILE "name of file.bin" BINARY
TRACK 01 MODE2/2352
INDEX 01 00:00:00
TRACK 02 MODE2/2352
INDEX 00 00:04:00
INDEX 01 00:06:00
Delete everything in the quotes, in this case we would
delete name of file.bin. Now place the title you copied
in between the quotes. Save the changes and close out.
Thats it, your .cue file should work now.
OTHER WAYS TO USE .BIN & .CUE FILES
VCDGear:
This program will allow you to extract MPEG streams from CD images, convert VCD files to MPEG, correct MPEG errors, and more.
Daemon Tools:
This program creates a virtual drive on your PC which will allow you to "mount" the .cue file and use whatever is in the .bin file without having to burn it to a cd.
ISOBuster:
This program will allow you to "bust" open the .bin file and extract the files within the .bin.
_________________
There always seems to be the question "what do I do with a .bin and .cue file" in these forums so I figured I would write a quick and simple tutorial. Please feel free to add more.
So you have downloaded two files, one with a .bin extension and one with a .cue extension. "What do I do with these?" you ask. There are a number of options.
BURN TO CD
You will need either NERO, CDRWIN or FIREBURNER to burn the file.
To burn with NERO:
Start NERO, choose FILE, choose BURN IMAGE, locate the .cue file you have and double click it. A dialog box will come up, for anything other than music make sure you choose DISC-AT-ONCE (DAO). You can also turn off the simulation burn if you so choose.
Then burn away.
To burn with CDRWin:
Start CDRWin, choose the button on the top left, choose LOAD CUESHEET, press START RECORDING.
To burn with Fireburner:
Start Fireburner, click on the button on the bottom left corner "VISUAL CUE BURNER/BINCHUNKER", press the right mouse button and choose LOAD TRACKS FROM .CUE and choose the correct .CUE file, press the right mouse button again and chooseselect "Burn/Test Burn", choose DISK AT ONCE (DAO), disable TEST BURN and MULTISESSION, press OK.
.CUE ERRORS
The most common error you will get with a .cue file is when it points to an incorrect path. This is easily fixed. Find the .bin file, copy the exact title including the .bin extension. Now find the .cue file, open the .cue file using notepad. It should look similar to this:
FILE "name of file.bin" BINARY
TRACK 01 MODE2/2352
INDEX 01 00:00:00
TRACK 02 MODE2/2352
INDEX 00 00:04:00
INDEX 01 00:06:00
Delete everything in the quotes, in this case we would
delete name of file.bin. Now place the title you copied
in between the quotes. Save the changes and close out.
Thats it, your .cue file should work now.
OTHER WAYS TO USE .BIN & .CUE FILES
VCDGear:
This program will allow you to extract MPEG streams from CD images, convert VCD files to MPEG, correct MPEG errors, and more.
Daemon Tools:
This program creates a virtual drive on your PC which will allow you to "mount" the .cue file and use whatever is in the .bin file without having to burn it to a cd.
ISOBuster:
This program will allow you to "bust" open the .bin file and extract the files within the .bin.
_________________
Sunday, October 17, 2010
5 Things You Never Knew Your Cell
5 Things You Never Knew Your Cell |
Phone Could Do
For all the folks with cell phones. (This should be printed and kept in your car, purse,and wallet. Good information to have with you.)
There are a few things that can be done in times of grave emergencies.
Your mobile phone can actually be a life saver or an emergency tool for survival.Check out the things that you can do with it:
For all the folks with cell phones. (This should be printed and kept in your car, purse,and wallet. Good information to have with you.)
There are a few things that can be done in times of grave emergencies.
Your mobile phone can actually be a life saver or an emergency tool for survival.Check out the things that you can do with it:
FIRSTEmergency;
The Emergency Number worldwide for Mobile is 112. If you find yourself out of the
coverage area of your mobile network and there is an emergency, dial 112 and the
mobile will search any existing network to establish the emergency number for you,
and interestingly, this number 112 can be dialed even if the keypad is locked. Try it out.
SECOND
Locked your keys in the car?
Does your car have remote keyless entry? This may come in handy someday. Good
Does your car have remote keyless entry? This may come in handy someday. Good
reason to own a cell phone: If you lock your keys in the car and the spare keys are at
home, call someone at home on their cell phone from your cell phone. Hold your
cell phone about a foot from your car door and have the person at your home press
the unlock button, holding it near the mobile phone on their end. Your car will unlock.
Saves someone from having to drive your keys to you. Distance is no object. You
could be hundreds of miles away, and if you can reach someone who has the other
'remote' for your car, you can unlock the doors or the trunk).
Editor's Note: Works fine! We tried it out and it unlocked our car over a cell phone!
Editor's Note: Works fine! We tried it out and it unlocked our car over a cell phone!
THIRDHidden Battery Power;
Imagine your cell battery is very low. To activate, press the keys *3370#. Your cell
Imagine your cell battery is very low. To activate, press the keys *3370#. Your cell
phone will restart with this reserve and the instrument will show a 50% increase in
battery. This reserve will get charged when you charge your cell phone next time.
FOURTHHow to disable a STOLEN m
To check your Mobile phone's obile phone?
serial number, key in the following Digits on your phone:
*#06#. A 15-digit code will appear on the screen. This number is unique to
your handset. Write it down and keep it somewhere safe.
If your phone gets stolen, you can phone your service provider and give them this code.
If your phone gets stolen, you can phone your service provider and give them this code.
They will then be able to block your handset so even if the thief changes the SIM card,
your phone will be totally useless.. You probably won't get your phone back, but at
least you know that whoever stole it can't use/sell it either. If everybody does this,
there would be no point in people stealing mobile phones.
And Finally.....
And Finally.....
FIFTHFree Directory Service for Cells;
Cell phone companies are charging us $1.00 to $1.75 or more for 411 information calls
when they don't have to. Most of us do not carry a telephone directory in our vehicle,
which makes this situation even more of a problem. When you need to use the 411
information option, simply dial: (800)FREE411 (800)FREE411 begin_of_the_skype_highlighting (800)FREE411 (800)FREE411 end_of_the_skype_highlighting, or (800) 373-3411 (800) 373-3411 begin_of_the_skype_highlighting (800) 373-3411 (800) 373-3411 end_of_the_skype_highlighting without incurring any charge at all. Program this into your cell phone now.
This is the kind of information people don't
This is the kind of information people don't
mind receiving, so pass it on to your family
and friends.
Friday, October 15, 2010
Backtracking EMAIL
Backtracking EMAIL Messages
Tracking email back to its source: Twisted Evil
cause i hate spammers... Evil or Very Mad
Ask most people how they determine who sent them an email message and the response is almost universally, "By the From line." Unfortunately this symptomatic of the current confusion among internet users as to where particular messages come from and who is spreading spam and viruses. The "From" header is little more than a courtesy to the person receiving the message. People spreading spam and viruses are rarely courteous. In short, if there is any question about where a particular email message came from the safe bet is to assume the "From" header is forged.
So how do you determine where a message actually came from? You have to understand how email messages are put together in order to backtrack an email message. SMTP is a text based protocol for transferring messages across the internet. A series of headers are placed in front of the data portion of the message. By examining the headers you can usually backtrack a message to the source network, sometimes the source host. A more detailed essay on reading email headers can be found .
If you are using Outlook or Outlook Express you can view the headers by right clicking on the message and selecting properties or options.
Below are listed the headers of an actual spam message I received. I've changed my email address and the name of my server for obvious reasons. I've also double spaced the headers to make them more readable.
Return-Path: <s359dyxtt@yahoo.com>
X-Original-To: davar@example.com
Delivered-To: davar@example.com
Received: from 12-218-172-108.client.mchsi.com (12-218-172-108.client.mchsi.com [12.218.172.108])
by mailhost.example.com (Postfix) with SMTP id 1F9B8511C7
for <davar@example.com>; Sun, 16 Nov 2003 09:50:37 -0800 (PST)
Received: from (HELO 0udjou) [193.12.169.0] by 12-218-172-108.client.mchsi.com with ESMTP id <536806-74276>; Sun, 16 Nov 2003 19:42:31 +0200
Message-ID: <n5-l067n7z$46-z$-n@eo2.32574>
From: "Maricela Paulson" <s359dyxtt@yahoo.com>
Reply-To: "Maricela Paulson" <s359dyxtt@yahoo.com>
To: davar@example.com
Subject: STOP-PAYING For Your PAY-PER-VIEW, Movie Channels, Mature Channels...isha
Date: Sun, 16 Nov 2003 19:42:31 +0200
X-Mailer: Internet Mail Service (5.5.2650.21)
X-Priority: 3
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="MIMEStream=_0+211404_90873633350646_4032088448"
According to the From header this message is from Maricela Paulson at s359dyxxt@yahoo.com. I could just fire off a message to abuse@yahoo.com, but that would be waste of time. This message didn't come from yahoo's email service.
The header most likely to be useful in determining the actual source of an email message is the Received header. According to the top-most Received header this message was received from the host 12-218-172-108.client.mchsi.com with the ip address of 21.218.172.108 by my server mailhost.example.com. An important item to consider is at what point in the chain does the email system become untrusted? I consider anything beyond my own email server to be an unreliable source of information. Because this header was generated by my email server it is reasonable for me to accept it at face value.
The next Received header (which is chronologically the first) shows the remote email server accepting the message from the host 0udjou with the ip 193.12.169.0. Those of you who know anything about IP will realize that that is not a valid host IP address. In addition, any hostname that ends in client.mchsi.com is unlikely to be an authorized email server. This has every sign of being a cracked client system.
Here's is where we start digging. By default Windows is somewhat lacking in network diagnostic tools; however, you can use the tools at to do your own checking.
davar@nqh9k:[/home/davar] $whois 12.218.172.108
AT&T WorldNet Services ATT (NET-12-0-0-0-1)
12.0.0.0 - 12.255.255.255
Mediacom Communications Corp MEDIACOMCC-12-218-168-0-FLANDREAU-MN (NET-12-218-168-0-1)
12.218.168.0 - 12.218.175.255
# ARIN WHOIS database, last updated 2003-12-31 19:15
# Enter ? for additional hints on searching ARIN's WHOIS database.
I can also verify the hostname of the remote server by using nslookup, although in this particular instance, my email server has already provided both the IP address and the hostname.
davar@nqh9k:[/home/davar] $nslookup 12.218.172.108
Server: localhost
Address: 127.0.0.1
Name: 12-218-172-108.client.mchsi.com
Address: 12.218.172.108
Ok, whois shows that Mediacom Communications owns that netblock and nslookup confirms the address to hostname mapping of the remote server,12-218-172-108.client.mchsi.com. If I preface a www in front of the domain name portion and plug that into my web browser, http://www.mchsi.com/, I get Mediacom's web site.
There are few things more embarrassing to me than firing off an angry message to someone who is supposedly responsible for a problem, and being wrong. By double checking who owns the remote host's IP address using two different tools (whois and nslookup) I minimize the chance of making myself look like an idiot.
A quick glance at the web site and it appears they are an ISP. Now if I copy the entire message including the headers into a new email message and send it to abuse@mchsi.com with a short message explaining the situation, they may do something about it.
But what about Maricela Paulson? There really is no way to determine who sent a message, the best you can hope for is to find out what host sent it. Even in the case of a PGP signed messages there is no guarantee that one particular person actually pressed the send button. Obviously determining who the actual sender of an email message is much more involved than reading the From header. Hopefully this example may be of some use to other forum regulars.
Tracking email back to its source: Twisted Evil
cause i hate spammers... Evil or Very Mad
Ask most people how they determine who sent them an email message and the response is almost universally, "By the From line." Unfortunately this symptomatic of the current confusion among internet users as to where particular messages come from and who is spreading spam and viruses. The "From" header is little more than a courtesy to the person receiving the message. People spreading spam and viruses are rarely courteous. In short, if there is any question about where a particular email message came from the safe bet is to assume the "From" header is forged.
So how do you determine where a message actually came from? You have to understand how email messages are put together in order to backtrack an email message. SMTP is a text based protocol for transferring messages across the internet. A series of headers are placed in front of the data portion of the message. By examining the headers you can usually backtrack a message to the source network, sometimes the source host. A more detailed essay on reading email headers can be found .
If you are using Outlook or Outlook Express you can view the headers by right clicking on the message and selecting properties or options.
Below are listed the headers of an actual spam message I received. I've changed my email address and the name of my server for obvious reasons. I've also double spaced the headers to make them more readable.
Return-Path: <s359dyxtt@yahoo.com>
X-Original-To: davar@example.com
Delivered-To: davar@example.com
Received: from 12-218-172-108.client.mchsi.com (12-218-172-108.client.mchsi.com [12.218.172.108])
by mailhost.example.com (Postfix) with SMTP id 1F9B8511C7
for <davar@example.com>; Sun, 16 Nov 2003 09:50:37 -0800 (PST)
Received: from (HELO 0udjou) [193.12.169.0] by 12-218-172-108.client.mchsi.com with ESMTP id <536806-74276>; Sun, 16 Nov 2003 19:42:31 +0200
Message-ID: <n5-l067n7z$46-z$-n@eo2.32574>
From: "Maricela Paulson" <s359dyxtt@yahoo.com>
Reply-To: "Maricela Paulson" <s359dyxtt@yahoo.com>
To: davar@example.com
Subject: STOP-PAYING For Your PAY-PER-VIEW, Movie Channels, Mature Channels...isha
Date: Sun, 16 Nov 2003 19:42:31 +0200
X-Mailer: Internet Mail Service (5.5.2650.21)
X-Priority: 3
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="MIMEStream=_0+211404_90873633350646_4032088448"
According to the From header this message is from Maricela Paulson at s359dyxxt@yahoo.com. I could just fire off a message to abuse@yahoo.com, but that would be waste of time. This message didn't come from yahoo's email service.
The header most likely to be useful in determining the actual source of an email message is the Received header. According to the top-most Received header this message was received from the host 12-218-172-108.client.mchsi.com with the ip address of 21.218.172.108 by my server mailhost.example.com. An important item to consider is at what point in the chain does the email system become untrusted? I consider anything beyond my own email server to be an unreliable source of information. Because this header was generated by my email server it is reasonable for me to accept it at face value.
The next Received header (which is chronologically the first) shows the remote email server accepting the message from the host 0udjou with the ip 193.12.169.0. Those of you who know anything about IP will realize that that is not a valid host IP address. In addition, any hostname that ends in client.mchsi.com is unlikely to be an authorized email server. This has every sign of being a cracked client system.
Here's is where we start digging. By default Windows is somewhat lacking in network diagnostic tools; however, you can use the tools at to do your own checking.
davar@nqh9k:[/home/davar] $whois 12.218.172.108
AT&T WorldNet Services ATT (NET-12-0-0-0-1)
12.0.0.0 - 12.255.255.255
Mediacom Communications Corp MEDIACOMCC-12-218-168-0-FLANDREAU-MN (NET-12-218-168-0-1)
12.218.168.0 - 12.218.175.255
# ARIN WHOIS database, last updated 2003-12-31 19:15
# Enter ? for additional hints on searching ARIN's WHOIS database.
I can also verify the hostname of the remote server by using nslookup, although in this particular instance, my email server has already provided both the IP address and the hostname.
davar@nqh9k:[/home/davar] $nslookup 12.218.172.108
Server: localhost
Address: 127.0.0.1
Name: 12-218-172-108.client.mchsi.com
Address: 12.218.172.108
Ok, whois shows that Mediacom Communications owns that netblock and nslookup confirms the address to hostname mapping of the remote server,12-218-172-108.client.mchsi.com. If I preface a www in front of the domain name portion and plug that into my web browser, http://www.mchsi.com/, I get Mediacom's web site.
There are few things more embarrassing to me than firing off an angry message to someone who is supposedly responsible for a problem, and being wrong. By double checking who owns the remote host's IP address using two different tools (whois and nslookup) I minimize the chance of making myself look like an idiot.
A quick glance at the web site and it appears they are an ISP. Now if I copy the entire message including the headers into a new email message and send it to abuse@mchsi.com with a short message explaining the situation, they may do something about it.
But what about Maricela Paulson? There really is no way to determine who sent a message, the best you can hope for is to find out what host sent it. Even in the case of a PGP signed messages there is no guarantee that one particular person actually pressed the send button. Obviously determining who the actual sender of an email message is much more involved than reading the From header. Hopefully this example may be of some use to other forum regulars.
A Basic Guide to the Internet
The Internet is a computer network made up of thousands of networks worldwide. No one knows exactly how many computers are connected to the Internet. It is certain, however, that these number in the millions.
No one is in charge of the Internet. There are organizations which develop technical aspects of this network and set standards for creating applications on it, but no governing body is in control. The Internet backbone, through which Internet traffic flows, is owned by private companies.
All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture. This means that the remote server machine provides files and services to the user's local client machine. Software can be installed on a client computer to take advantage of the latest access technology.
An Internet user has access to a wide variety of services: electronic mail, file transfer, vast information resources, interest group membership, interactive collaboration, multimedia displays, real-time broadcasting, shopping opportunities, breaking news, and much more.
The Internet consists primarily of a variety of access protocols. Many of these protocols feature programs that allow users to search for and retrieve material made available by the protocol.
--------------------------------------------------------------------------------
COMPONENTS OF THE INTERNET
--------------------------------------------------------------------------------
WORLD WIDE WEB
The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. Almost every protocol type available on the Internet is accessible on the Web. This includes e-mail, FTP, Telnet, and Usenet News. In addition to these, the World Wide Web has its own protocol: HyperText Transfer Protocol, or HTTP. These protocols will be explained later in this document.
The World Wide Web provides a single interface for accessing all these protocols. This creates a convenient and user-friendly environment. It is no longer necessary to be conversant in these protocols within separate, command-level environments. The Web gathers together these protocols into a single system. Because of this feature, and because of the Web's ability to work with multimedia and advanced programming languages, the Web is the fastest-growing component of the Internet.
The operation of the Web relies primarily on hypertext as its means of information retrieval. HyperText is a document containing words that connect to other documents. These words are called links and are selectable by the user. A single hypertext document can contain links to many documents. In the context of the Web, words or graphics may serve as links to other documents, images, video, and sound. Links may or may not follow a logical path, as each connection is programmed by the creator of the source document. Overall, the Web contains a complex virtual web of connections among a vast number of documents, graphics, videos, and sounds.
Producing hypertext for the Web is accomplished by creating documents with a language called HyperText Markup Language, or HTML. With HTML, tags are placed within the text to accomplish document formatting, visual features such as font size, italics and bold, and the creation of hypertext links. Graphics and multimedia may also be incorporated into an HTML document. HTML is an evolving language, with new tags being added as each upgrade of the language is developed and released. The World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee, coordinates the efforts of standardizing HTML. The W3C now calls the language XHTML and considers it to be an application of the XML language standard.
The World Wide Web consists of files, called pages or home pages, containing links to documents and resources throughout the Internet.
The Web provides a vast array of experiences including multimedia presentations, real-time collaboration, interactive pages, radio and television broadcasts, and the automatic "push" of information to a client computer. Programming languages such as Java, JavaScript, Visual Basic, Cold Fusion and XML are extending the capabilities of the Web. A growing amount of information on the Web is served dynamically from content stored in databases. The Web is therefore not a fixed entity, but one that is in a constant state of development and flux.
For more complete information about the World Wide Web, see Understanding The World Wide Web.
E-MAIL
Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.
A powerful aspect of e-mail is the option to send electronic files to a person's e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types. For example, a document created in Microsoft Word can be attached to an e-mail message and retrieved by the recipient with the appropriate e-mail program. Many e-mail programs, including Eudora, Netscape Messenger, and Microsoft Outlook, offer the ability to read files written in HTML, which is itself a MIME type.
TELNET
Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more. There are no graphics in Telnet sessions, just text. To Telnet to a computer, you must know its address. This can consist of words (locis.loc.gov) or numbers (140.147.254.3). Some services require you to connect to a specific port on the remote computer. In this case, type the port number after the Internet address. Example: telnet nri.reston.va.us 185.
Telnet is available on the World Wide Web. Probably the most common Web-based resources available through Telnet have been library catalogs, though most catalogs have since migrated to the Web. A link to a Telnet resource may look like any other link, but it will launch a Telnet session to make the connection. A Telnet program must be installed on your local computer and configured to your Web browser in order to work.
With the increasing popularity of the Web, Telnet has become less frequently used as a means of access to information on the Internet.
FTP
FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account. FTP sites contain books, articles, software, games, images, sounds, multimedia, course work, data sets, and more.
If your computer is directly connected to the Internet via an Ethernet cable, you can use one of several PC software programs, such as WS_FTP for Windows, to conduct a file transfer.
FTP transfers can be performed on the World Wide Web without the need for special software. In this case, the Web browser will suffice. Whenever you download software from a Web site to your local machine, you are using FTP. You can also retrieve FTP files via search engines such as FtpFind, located at /http://www.ftpfind.com/. This option is easiest because you do not need to know FTP program commands.
E-MAIL DISCUSSION GROUPS
One of the benefits of the Internet is the opportunity it offers to people worldwide to communicate via e-mail. The Internet is home to a large community of individuals who carry out active discussions organized around topic-oriented forums distributed by e-mail. These are administered by software programs. Probably the most common program is the listserv.
A great variety of topics are covered by listservs, many of them academic in nature. When you subscribe to a listserv, messages from other subscribers are automatically sent to your electronic mailbox. You subscribe to a listserv by sending an e-mail message to a computer program called a listserver. Listservers are located on computer networks throughout the world. This program handles subscription information and distributes messages to and from subscribers. You must have a e-mail account to participate in a listserv discussion group. Visit Tile.net at /http://tile.net/ to see an example of a site that offers a searchablecollection of e-mail discussion groups.
Majordomo and Listproc are two other programs that administer e-mail discussion groups. The commands for subscribing to and managing your list memberships are similar to those of listserv.
USENET NEWS
Usenet News is a global electronic bulletin board system in which millions of computer users exchange information on a vast range of topics. The major difference between Usenet News and e-mail discussion groups is the fact that Usenet messages are stored on central computers, and users must connect to these computers to read or download the messages posted to these groups. This is distinct from e-mail distribution, in which messages arrive in the electronic mailboxes of each list member.
Usenet itself is a set of machines that exchanges messages, or articles, from Usenet discussion forums, called newsgroups. Usenet administrators control their own sites, and decide which (if any) newsgroups to sponsor and which remote newsgroups to allow into the system.
There are thousands of Usenet newsgroups in existence. While many are academic in nature, numerous newsgroups are organized around recreational topics. Much serious computer-related work takes place in Usenet discussions. A small number of e-mail discussion groups also exist as Usenet newsgroups.
The Usenet newsfeed can be read by a variety of newsreader software programs. For example, the Netscape suite comes with a newsreader program called Messenger. Newsreaders are also available as standalone products.
FAQ, RFC, FYI
FAQ stands for Frequently Asked Questions. These are periodic postings to Usenet newsgroups that contain a wealth of information related to the topic of the newsgroup. Many FAQs are quite extensive. FAQs are available by subscribing to individual Usenet newsgroups. A Web-based collection of FAQ resources has been collected by The Internet FAQ Consortium and is available at /http://www.faqs.org/.
RFC stands for Request for Comments. These are documents created by and distributed to the Internet community to help define the nuts and bolts of the Internet. They contain both technical specifications and general information.
FYI stands for For Your Information. These notes are a subset of RFCs and contain information of interest to new Internet users.
Links to indexes of all three of these information resources are available on the University Libraries Web site at /http://library.albany.edu/reference/faqs.html.
CHAT & INSTANT MESSENGING
Chat programs allow users on the Internet to communicate with each other by typing in real time. They are sometimes included as a feature of a Web site, where users can log into the "chat room" to exchange comments and information about the topics addressed on the site. Chat may take other, more wide-ranging forms. For example, America Online is well known for sponsoring a number of topical chat rooms.
Internet Relay Chat (IRC) is a service through which participants can communicate to each other on hundreds of channels. These channels are usually based on specific topics. While many topics are frivolous, substantive conversations are also taking place. To access IRC, you must use an IRC software program.
A variation of chat is the phenomenon of instant messenging. With instant messenging, a user on the Web can contact another user currently logged in and type a conversation. Most famous is America Online's Instant Messenger. ICQ, MSN and Yahoo are other commonly-used chat programs.
Other types of real-time communication are addressed in the tutorial Understanding the World Wide Web.
MUD/MUSH/MOO/MUCK/DUM/MUSE
MUD stands for Multi User Dimension. MUDs, and their variations listed above, are multi-user virtual reality games based on simulated worlds. Traditionally text based, graphical MUDs now exist. There are MUDs of all kinds on the Internet, and many can be joined free of charge. For more information, read one of the FAQs devoted to MUDs available at the FAQ site at
No one is in charge of the Internet. There are organizations which develop technical aspects of this network and set standards for creating applications on it, but no governing body is in control. The Internet backbone, through which Internet traffic flows, is owned by private companies.
All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture. This means that the remote server machine provides files and services to the user's local client machine. Software can be installed on a client computer to take advantage of the latest access technology.
An Internet user has access to a wide variety of services: electronic mail, file transfer, vast information resources, interest group membership, interactive collaboration, multimedia displays, real-time broadcasting, shopping opportunities, breaking news, and much more.
The Internet consists primarily of a variety of access protocols. Many of these protocols feature programs that allow users to search for and retrieve material made available by the protocol.
--------------------------------------------------------------------------------
COMPONENTS OF THE INTERNET
--------------------------------------------------------------------------------
WORLD WIDE WEB
The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. Almost every protocol type available on the Internet is accessible on the Web. This includes e-mail, FTP, Telnet, and Usenet News. In addition to these, the World Wide Web has its own protocol: HyperText Transfer Protocol, or HTTP. These protocols will be explained later in this document.
The World Wide Web provides a single interface for accessing all these protocols. This creates a convenient and user-friendly environment. It is no longer necessary to be conversant in these protocols within separate, command-level environments. The Web gathers together these protocols into a single system. Because of this feature, and because of the Web's ability to work with multimedia and advanced programming languages, the Web is the fastest-growing component of the Internet.
The operation of the Web relies primarily on hypertext as its means of information retrieval. HyperText is a document containing words that connect to other documents. These words are called links and are selectable by the user. A single hypertext document can contain links to many documents. In the context of the Web, words or graphics may serve as links to other documents, images, video, and sound. Links may or may not follow a logical path, as each connection is programmed by the creator of the source document. Overall, the Web contains a complex virtual web of connections among a vast number of documents, graphics, videos, and sounds.
Producing hypertext for the Web is accomplished by creating documents with a language called HyperText Markup Language, or HTML. With HTML, tags are placed within the text to accomplish document formatting, visual features such as font size, italics and bold, and the creation of hypertext links. Graphics and multimedia may also be incorporated into an HTML document. HTML is an evolving language, with new tags being added as each upgrade of the language is developed and released. The World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee, coordinates the efforts of standardizing HTML. The W3C now calls the language XHTML and considers it to be an application of the XML language standard.
The World Wide Web consists of files, called pages or home pages, containing links to documents and resources throughout the Internet.
The Web provides a vast array of experiences including multimedia presentations, real-time collaboration, interactive pages, radio and television broadcasts, and the automatic "push" of information to a client computer. Programming languages such as Java, JavaScript, Visual Basic, Cold Fusion and XML are extending the capabilities of the Web. A growing amount of information on the Web is served dynamically from content stored in databases. The Web is therefore not a fixed entity, but one that is in a constant state of development and flux.
For more complete information about the World Wide Web, see Understanding The World Wide Web.
Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.
A powerful aspect of e-mail is the option to send electronic files to a person's e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types. For example, a document created in Microsoft Word can be attached to an e-mail message and retrieved by the recipient with the appropriate e-mail program. Many e-mail programs, including Eudora, Netscape Messenger, and Microsoft Outlook, offer the ability to read files written in HTML, which is itself a MIME type.
TELNET
Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more. There are no graphics in Telnet sessions, just text. To Telnet to a computer, you must know its address. This can consist of words (locis.loc.gov) or numbers (140.147.254.3). Some services require you to connect to a specific port on the remote computer. In this case, type the port number after the Internet address. Example: telnet nri.reston.va.us 185.
Telnet is available on the World Wide Web. Probably the most common Web-based resources available through Telnet have been library catalogs, though most catalogs have since migrated to the Web. A link to a Telnet resource may look like any other link, but it will launch a Telnet session to make the connection. A Telnet program must be installed on your local computer and configured to your Web browser in order to work.
With the increasing popularity of the Web, Telnet has become less frequently used as a means of access to information on the Internet.
FTP
FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account. FTP sites contain books, articles, software, games, images, sounds, multimedia, course work, data sets, and more.
If your computer is directly connected to the Internet via an Ethernet cable, you can use one of several PC software programs, such as WS_FTP for Windows, to conduct a file transfer.
FTP transfers can be performed on the World Wide Web without the need for special software. In this case, the Web browser will suffice. Whenever you download software from a Web site to your local machine, you are using FTP. You can also retrieve FTP files via search engines such as FtpFind, located at /http://www.ftpfind.com/. This option is easiest because you do not need to know FTP program commands.
E-MAIL DISCUSSION GROUPS
One of the benefits of the Internet is the opportunity it offers to people worldwide to communicate via e-mail. The Internet is home to a large community of individuals who carry out active discussions organized around topic-oriented forums distributed by e-mail. These are administered by software programs. Probably the most common program is the listserv.
A great variety of topics are covered by listservs, many of them academic in nature. When you subscribe to a listserv, messages from other subscribers are automatically sent to your electronic mailbox. You subscribe to a listserv by sending an e-mail message to a computer program called a listserver. Listservers are located on computer networks throughout the world. This program handles subscription information and distributes messages to and from subscribers. You must have a e-mail account to participate in a listserv discussion group. Visit Tile.net at /http://tile.net/ to see an example of a site that offers a searchablecollection of e-mail discussion groups.
Majordomo and Listproc are two other programs that administer e-mail discussion groups. The commands for subscribing to and managing your list memberships are similar to those of listserv.
USENET NEWS
Usenet News is a global electronic bulletin board system in which millions of computer users exchange information on a vast range of topics. The major difference between Usenet News and e-mail discussion groups is the fact that Usenet messages are stored on central computers, and users must connect to these computers to read or download the messages posted to these groups. This is distinct from e-mail distribution, in which messages arrive in the electronic mailboxes of each list member.
Usenet itself is a set of machines that exchanges messages, or articles, from Usenet discussion forums, called newsgroups. Usenet administrators control their own sites, and decide which (if any) newsgroups to sponsor and which remote newsgroups to allow into the system.
There are thousands of Usenet newsgroups in existence. While many are academic in nature, numerous newsgroups are organized around recreational topics. Much serious computer-related work takes place in Usenet discussions. A small number of e-mail discussion groups also exist as Usenet newsgroups.
The Usenet newsfeed can be read by a variety of newsreader software programs. For example, the Netscape suite comes with a newsreader program called Messenger. Newsreaders are also available as standalone products.
FAQ, RFC, FYI
FAQ stands for Frequently Asked Questions. These are periodic postings to Usenet newsgroups that contain a wealth of information related to the topic of the newsgroup. Many FAQs are quite extensive. FAQs are available by subscribing to individual Usenet newsgroups. A Web-based collection of FAQ resources has been collected by The Internet FAQ Consortium and is available at /http://www.faqs.org/.
RFC stands for Request for Comments. These are documents created by and distributed to the Internet community to help define the nuts and bolts of the Internet. They contain both technical specifications and general information.
FYI stands for For Your Information. These notes are a subset of RFCs and contain information of interest to new Internet users.
Links to indexes of all three of these information resources are available on the University Libraries Web site at /http://library.albany.edu/reference/faqs.html.
CHAT & INSTANT MESSENGING
Chat programs allow users on the Internet to communicate with each other by typing in real time. They are sometimes included as a feature of a Web site, where users can log into the "chat room" to exchange comments and information about the topics addressed on the site. Chat may take other, more wide-ranging forms. For example, America Online is well known for sponsoring a number of topical chat rooms.
Internet Relay Chat (IRC) is a service through which participants can communicate to each other on hundreds of channels. These channels are usually based on specific topics. While many topics are frivolous, substantive conversations are also taking place. To access IRC, you must use an IRC software program.
A variation of chat is the phenomenon of instant messenging. With instant messenging, a user on the Web can contact another user currently logged in and type a conversation. Most famous is America Online's Instant Messenger. ICQ, MSN and Yahoo are other commonly-used chat programs.
Other types of real-time communication are addressed in the tutorial Understanding the World Wide Web.
MUD/MUSH/MOO/MUCK/DUM/MUSE
MUD stands for Multi User Dimension. MUDs, and their variations listed above, are multi-user virtual reality games based on simulated worlds. Traditionally text based, graphical MUDs now exist. There are MUDs of all kinds on the Internet, and many can be joined free of charge. For more information, read one of the FAQs devoted to MUDs available at the FAQ site at
Wednesday, October 13, 2010
A Basic Guide to the Internet
The Internet is a computer network made up of thousands of networks worldwide. No one knows exactly how many computers are connected to the Internet. It is certain, however, that these number in the millions.
No one is in charge of the Internet. There are organizations which develop technical aspects of this network and set standards for creating applications on it, but no governing body is in control. The Internet backbone, through which Internet traffic flows, is owned by private companies.
All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture. This means that the remote server machine provides files and services to the user's local client machine. Software can be installed on a client computer to take advantage of the latest access technology.
An Internet user has access to a wide variety of services: electronic mail, file transfer, vast information resources, interest group membership, interactive collaboration, multimedia displays, real-time broadcasting, shopping opportunities, breaking news, and much more.
The Internet consists primarily of a variety of access protocols. Many of these protocols feature programs that allow users to search for and retrieve material made available by the protocol.
--------------------------------------------------------------------------------
COMPONENTS OF THE INTERNET
--------------------------------------------------------------------------------
WORLD WIDE WEB
The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. Almost every protocol type available on the Internet is accessible on the Web. This includes e-mail, FTP, Telnet, and Usenet News. In addition to these, the World Wide Web has its own protocol: HyperText Transfer Protocol, or HTTP. These protocols will be explained later in this document.
The World Wide Web provides a single interface for accessing all these protocols. This creates a convenient and user-friendly environment. It is no longer necessary to be conversant in these protocols within separate, command-level environments. The Web gathers together these protocols into a single system. Because of this feature, and because of the Web's ability to work with multimedia and advanced programming languages, the Web is the fastest-growing component of the Internet.
The operation of the Web relies primarily on hypertext as its means of information retrieval. HyperText is a document containing words that connect to other documents. These words are called links and are selectable by the user. A single hypertext document can contain links to many documents. In the context of the Web, words or graphics may serve as links to other documents, images, video, and sound. Links may or may not follow a logical path, as each connection is programmed by the creator of the source document. Overall, the Web contains a complex virtual web of connections among a vast number of documents, graphics, videos, and sounds.
Producing hypertext for the Web is accomplished by creating documents with a language called HyperText Markup Language, or HTML. With HTML, tags are placed within the text to accomplish document formatting, visual features such as font size, italics and bold, and the creation of hypertext links. Graphics and multimedia may also be incorporated into an HTML document. HTML is an evolving language, with new tags being added as each upgrade of the language is developed and released. The World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee, coordinates the efforts of standardizing HTML. The W3C now calls the language XHTML and considers it to be an application of the XML language standard.
The World Wide Web consists of files, called pages or home pages, containing links to documents and resources throughout the Internet.
The Web provides a vast array of experiences including multimedia presentations, real-time collaboration, interactive pages, radio and television broadcasts, and the automatic "push" of information to a client computer. Programming languages such as Java, JavaScript, Visual Basic, Cold Fusion and XML are extending the capabilities of the Web. A growing amount of information on the Web is served dynamically from content stored in databases. The Web is therefore not a fixed entity, but one that is in a constant state of development and flux.
For more complete information about the World Wide Web, see Understanding The World Wide Web.
E-MAIL
Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.
A powerful aspect of e-mail is the option to send electronic files to a person's e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types. For example, a document created in Microsoft Word can be attached to an e-mail message and retrieved by the recipient with the appropriate e-mail program. Many e-mail programs, including Eudora, Netscape Messenger, and Microsoft Outlook, offer the ability to read files written in HTML, which is itself a MIME type.
TELNET
Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more. There are no graphics in Telnet sessions, just text. To Telnet to a computer, you must know its address. This can consist of words (locis.loc.gov) or numbers (140.147.254.3). Some services require you to connect to a specific port on the remote computer. In this case, type the port number after the Internet address. Example: telnet nri.reston.va.us 185.
Telnet is available on the World Wide Web. Probably the most common Web-based resources available through Telnet have been library catalogs, though most catalogs have since migrated to the Web. A link to a Telnet resource may look like any other link, but it will launch a Telnet session to make the connection. A Telnet program must be installed on your local computer and configured to your Web browser in order to work.
With the increasing popularity of the Web, Telnet has become less frequently used as a means of access to information on the Internet.
FTP
FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account. FTP sites contain books, articles, software, games, images, sounds, multimedia, course work, data sets, and more.
If your computer is directly connected to the Internet via an Ethernet cable, you can use one of several PC software programs, such as WS_FTP for Windows, to conduct a file transfer.
FTP transfers can be performed on the World Wide Web without the need for special software. In this case, the Web browser will suffice. Whenever you download software from a Web site to your local machine, you are using FTP. You can also retrieve FTP files via search engines such as FtpFind, located at /http://www.ftpfind.com/. This option is easiest because you do not need to know FTP program commands.
E-MAIL DISCUSSION GROUPS
One of the benefits of the Internet is the opportunity it offers to people worldwide to communicate via e-mail. The Internet is home to a large community of individuals who carry out active discussions organized around topic-oriented forums distributed by e-mail. These are administered by software programs. Probably the most common program is the listserv.
A great variety of topics are covered by listservs, many of them academic in nature. When you subscribe to a listserv, messages from other subscribers are automatically sent to your electronic mailbox. You subscribe to a listserv by sending an e-mail message to a computer program called a listserver. Listservers are located on computer networks throughout the world. This program handles subscription information and distributes messages to and from subscribers. You must have a e-mail account to participate in a listserv discussion group. Visit Tile.net at /http://tile.net/ to see an example of a site that offers a searchablecollection of e-mail discussion groups.
Majordomo and Listproc are two other programs that administer e-mail discussion groups. The commands for subscribing to and managing your list memberships are similar to those of listserv.
USENET NEWS
Usenet News is a global electronic bulletin board system in which millions of computer users exchange information on a vast range of topics. The major difference between Usenet News and e-mail discussion groups is the fact that Usenet messages are stored on central computers, and users must connect to these computers to read or download the messages posted to these groups. This is distinct from e-mail distribution, in which messages arrive in the electronic mailboxes of each list member.
Usenet itself is a set of machines that exchanges messages, or articles, from Usenet discussion forums, called newsgroups. Usenet administrators control their own sites, and decide which (if any) newsgroups to sponsor and which remote newsgroups to allow into the system.
There are thousands of Usenet newsgroups in existence. While many are academic in nature, numerous newsgroups are organized around recreational topics. Much serious computer-related work takes place in Usenet discussions. A small number of e-mail discussion groups also exist as Usenet newsgroups.
The Usenet newsfeed can be read by a variety of newsreader software programs. For example, the Netscape suite comes with a newsreader program called Messenger. Newsreaders are also available as standalone products.
FAQ, RFC, FYI
FAQ stands for Frequently Asked Questions. These are periodic postings to Usenet newsgroups that contain a wealth of information related to the topic of the newsgroup. Many FAQs are quite extensive. FAQs are available by subscribing to individual Usenet newsgroups. A Web-based collection of FAQ resources has been collected by The Internet FAQ Consortium and is available at /http://www.faqs.org/.
RFC stands for Request for Comments. These are documents created by and distributed to the Internet community to help define the nuts and bolts of the Internet. They contain both technical specifications and general information.
FYI stands for For Your Information. These notes are a subset of RFCs and contain information of interest to new Internet users.
Links to indexes of all three of these information resources are available on the University Libraries Web site at /http://library.albany.edu/reference/faqs.html.
CHAT & INSTANT MESSENGING
Chat programs allow users on the Internet to communicate with each other by typing in real time. They are sometimes included as a feature of a Web site, where users can log into the "chat room" to exchange comments and information about the topics addressed on the site. Chat may take other, more wide-ranging forms. For example, America Online is well known for sponsoring a number of topical chat rooms.
Internet Relay Chat (IRC) is a service through which participants can communicate to each other on hundreds of channels. These channels are usually based on specific topics. While many topics are frivolous, substantive conversations are also taking place. To access IRC, you must use an IRC software program.
A variation of chat is the phenomenon of instant messenging. With instant messenging, a user on the Web can contact another user currently logged in and type a conversation. Most famous is America Online's Instant Messenger. ICQ, MSN and Yahoo are other commonly-used chat programs.
Other types of real-time communication are addressed in the tutorial Understanding the World Wide Web.
MUD/MUSH/MOO/MUCK/DUM/MUSE
MUD stands for Multi User Dimension. MUDs, and their variations listed above, are multi-user virtual reality games based on simulated worlds. Traditionally text based, graphical MUDs now exist. There are MUDs of all kinds on the Internet, and many can be joined free of charge. For more information, read one of the FAQs devoted to MUDs available at the FAQ site at
No one is in charge of the Internet. There are organizations which develop technical aspects of this network and set standards for creating applications on it, but no governing body is in control. The Internet backbone, through which Internet traffic flows, is owned by private companies.
All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture. This means that the remote server machine provides files and services to the user's local client machine. Software can be installed on a client computer to take advantage of the latest access technology.
An Internet user has access to a wide variety of services: electronic mail, file transfer, vast information resources, interest group membership, interactive collaboration, multimedia displays, real-time broadcasting, shopping opportunities, breaking news, and much more.
The Internet consists primarily of a variety of access protocols. Many of these protocols feature programs that allow users to search for and retrieve material made available by the protocol.
--------------------------------------------------------------------------------
COMPONENTS OF THE INTERNET
--------------------------------------------------------------------------------
WORLD WIDE WEB
The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. Almost every protocol type available on the Internet is accessible on the Web. This includes e-mail, FTP, Telnet, and Usenet News. In addition to these, the World Wide Web has its own protocol: HyperText Transfer Protocol, or HTTP. These protocols will be explained later in this document.
The World Wide Web provides a single interface for accessing all these protocols. This creates a convenient and user-friendly environment. It is no longer necessary to be conversant in these protocols within separate, command-level environments. The Web gathers together these protocols into a single system. Because of this feature, and because of the Web's ability to work with multimedia and advanced programming languages, the Web is the fastest-growing component of the Internet.
The operation of the Web relies primarily on hypertext as its means of information retrieval. HyperText is a document containing words that connect to other documents. These words are called links and are selectable by the user. A single hypertext document can contain links to many documents. In the context of the Web, words or graphics may serve as links to other documents, images, video, and sound. Links may or may not follow a logical path, as each connection is programmed by the creator of the source document. Overall, the Web contains a complex virtual web of connections among a vast number of documents, graphics, videos, and sounds.
Producing hypertext for the Web is accomplished by creating documents with a language called HyperText Markup Language, or HTML. With HTML, tags are placed within the text to accomplish document formatting, visual features such as font size, italics and bold, and the creation of hypertext links. Graphics and multimedia may also be incorporated into an HTML document. HTML is an evolving language, with new tags being added as each upgrade of the language is developed and released. The World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee, coordinates the efforts of standardizing HTML. The W3C now calls the language XHTML and considers it to be an application of the XML language standard.
The World Wide Web consists of files, called pages or home pages, containing links to documents and resources throughout the Internet.
The Web provides a vast array of experiences including multimedia presentations, real-time collaboration, interactive pages, radio and television broadcasts, and the automatic "push" of information to a client computer. Programming languages such as Java, JavaScript, Visual Basic, Cold Fusion and XML are extending the capabilities of the Web. A growing amount of information on the Web is served dynamically from content stored in databases. The Web is therefore not a fixed entity, but one that is in a constant state of development and flux.
For more complete information about the World Wide Web, see Understanding The World Wide Web.
Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.
A powerful aspect of e-mail is the option to send electronic files to a person's e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types. For example, a document created in Microsoft Word can be attached to an e-mail message and retrieved by the recipient with the appropriate e-mail program. Many e-mail programs, including Eudora, Netscape Messenger, and Microsoft Outlook, offer the ability to read files written in HTML, which is itself a MIME type.
TELNET
Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more. There are no graphics in Telnet sessions, just text. To Telnet to a computer, you must know its address. This can consist of words (locis.loc.gov) or numbers (140.147.254.3). Some services require you to connect to a specific port on the remote computer. In this case, type the port number after the Internet address. Example: telnet nri.reston.va.us 185.
Telnet is available on the World Wide Web. Probably the most common Web-based resources available through Telnet have been library catalogs, though most catalogs have since migrated to the Web. A link to a Telnet resource may look like any other link, but it will launch a Telnet session to make the connection. A Telnet program must be installed on your local computer and configured to your Web browser in order to work.
With the increasing popularity of the Web, Telnet has become less frequently used as a means of access to information on the Internet.
FTP
FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account. FTP sites contain books, articles, software, games, images, sounds, multimedia, course work, data sets, and more.
If your computer is directly connected to the Internet via an Ethernet cable, you can use one of several PC software programs, such as WS_FTP for Windows, to conduct a file transfer.
FTP transfers can be performed on the World Wide Web without the need for special software. In this case, the Web browser will suffice. Whenever you download software from a Web site to your local machine, you are using FTP. You can also retrieve FTP files via search engines such as FtpFind, located at /http://www.ftpfind.com/. This option is easiest because you do not need to know FTP program commands.
E-MAIL DISCUSSION GROUPS
One of the benefits of the Internet is the opportunity it offers to people worldwide to communicate via e-mail. The Internet is home to a large community of individuals who carry out active discussions organized around topic-oriented forums distributed by e-mail. These are administered by software programs. Probably the most common program is the listserv.
A great variety of topics are covered by listservs, many of them academic in nature. When you subscribe to a listserv, messages from other subscribers are automatically sent to your electronic mailbox. You subscribe to a listserv by sending an e-mail message to a computer program called a listserver. Listservers are located on computer networks throughout the world. This program handles subscription information and distributes messages to and from subscribers. You must have a e-mail account to participate in a listserv discussion group. Visit Tile.net at /http://tile.net/ to see an example of a site that offers a searchablecollection of e-mail discussion groups.
Majordomo and Listproc are two other programs that administer e-mail discussion groups. The commands for subscribing to and managing your list memberships are similar to those of listserv.
USENET NEWS
Usenet News is a global electronic bulletin board system in which millions of computer users exchange information on a vast range of topics. The major difference between Usenet News and e-mail discussion groups is the fact that Usenet messages are stored on central computers, and users must connect to these computers to read or download the messages posted to these groups. This is distinct from e-mail distribution, in which messages arrive in the electronic mailboxes of each list member.
Usenet itself is a set of machines that exchanges messages, or articles, from Usenet discussion forums, called newsgroups. Usenet administrators control their own sites, and decide which (if any) newsgroups to sponsor and which remote newsgroups to allow into the system.
There are thousands of Usenet newsgroups in existence. While many are academic in nature, numerous newsgroups are organized around recreational topics. Much serious computer-related work takes place in Usenet discussions. A small number of e-mail discussion groups also exist as Usenet newsgroups.
The Usenet newsfeed can be read by a variety of newsreader software programs. For example, the Netscape suite comes with a newsreader program called Messenger. Newsreaders are also available as standalone products.
FAQ, RFC, FYI
FAQ stands for Frequently Asked Questions. These are periodic postings to Usenet newsgroups that contain a wealth of information related to the topic of the newsgroup. Many FAQs are quite extensive. FAQs are available by subscribing to individual Usenet newsgroups. A Web-based collection of FAQ resources has been collected by The Internet FAQ Consortium and is available at /http://www.faqs.org/.
RFC stands for Request for Comments. These are documents created by and distributed to the Internet community to help define the nuts and bolts of the Internet. They contain both technical specifications and general information.
FYI stands for For Your Information. These notes are a subset of RFCs and contain information of interest to new Internet users.
Links to indexes of all three of these information resources are available on the University Libraries Web site at /http://library.albany.edu/reference/faqs.html.
CHAT & INSTANT MESSENGING
Chat programs allow users on the Internet to communicate with each other by typing in real time. They are sometimes included as a feature of a Web site, where users can log into the "chat room" to exchange comments and information about the topics addressed on the site. Chat may take other, more wide-ranging forms. For example, America Online is well known for sponsoring a number of topical chat rooms.
Internet Relay Chat (IRC) is a service through which participants can communicate to each other on hundreds of channels. These channels are usually based on specific topics. While many topics are frivolous, substantive conversations are also taking place. To access IRC, you must use an IRC software program.
A variation of chat is the phenomenon of instant messenging. With instant messenging, a user on the Web can contact another user currently logged in and type a conversation. Most famous is America Online's Instant Messenger. ICQ, MSN and Yahoo are other commonly-used chat programs.
Other types of real-time communication are addressed in the tutorial Understanding the World Wide Web.
MUD/MUSH/MOO/MUCK/DUM/MUSE
MUD stands for Multi User Dimension. MUDs, and their variations listed above, are multi-user virtual reality games based on simulated worlds. Traditionally text based, graphical MUDs now exist. There are MUDs of all kinds on the Internet, and many can be joined free of charge. For more information, read one of the FAQs devoted to MUDs available at the FAQ site at
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20 Great Google Secrets
http://www.pcmag.com/article2/0,4149,1306756,00.asp
excl.gif No Active Links, Read the Rules - Edit by Ninja excl.gif
Google is clearly the best general-purpose search engine on the Web (see
www.pcmag.com/searchengines
But most people don't use it to its best advantage. Do you just plug in a keyword or two and hope for the best? That may be the quickest way to search, but with more than 3 billion pages in Google's index, it's still a struggle to pare results to a manageable number.
But Google is an remarkably powerful tool that can ease and enhance your Internet exploration. Google's search options go beyond simple keywords, the Web, and even its own programmers. Let's look at some of Google's lesser-known options.
Syntax Search Tricks
Using a special syntax is a way to tell Google that you want to restrict your searches to certain elements or characteristics of Web pages. Google has a fairly complete list of its syntax elements at
www.google.com/help/operators.html
. Here are some advanced operators that can help narrow down your search results.
Intitle: at the beginning of a query word or phrase (intitle:"Three Blind Mice") restricts your search results to just the titles of Web pages.
Intext: does the opposite of intitle:, searching only the body text, ignoring titles, links, and so forth. Intext: is perfect when what you're searching for might commonly appear in URLs. If you're looking for the term HTML, for example, and you don't want to get results such as
www.mysite.com/index.html
, you can enter intext:html.
Link: lets you see which pages are linking to your Web page or to another page you're interested in. For example, try typing in
link:http://www.pcmag.com
Try using site: (which restricts results to top-level domains) with intitle: to find certain types of pages. For example, get scholarly pages about Mark Twain by searching for intitle:"Mark Twain"site:edu. Experiment with mixing various elements; you'll develop several strategies for finding the stuff you want more effectively. The site: command is very helpful as an alternative to the mediocre search engines built into many sites.
Swiss Army Google
Google has a number of services that can help you accomplish tasks you may never have thought to use Google for. For example, the new calculator feature
(www.google.com/help/features.html#calculator)
lets you do both math and a variety of conversions from the search box. For extra fun, try the query "Answer to life the universe and everything."
Let Google help you figure out whether you've got the right spelling—and the right word—for your search. Enter a misspelled word or phrase into the query box (try "thre blund mise") and Google may suggest a proper spelling. This doesn't always succeed; it works best when the word you're searching for can be found in a dictionary. Once you search for a properly spelled word, look at the results page, which repeats your query. (If you're searching for "three blind mice," underneath the search window will appear a statement such as Searched the web for "three blind mice.") You'll discover that you can click on each word in your search phrase and get a definition from a dictionary.
Suppose you want to contact someone and don't have his phone number handy. Google can help you with that, too. Just enter a name, city, and state. (The city is optional, but you must enter a state.) If a phone number matches the listing, you'll see it at the top of the search results along with a map link to the address. If you'd rather restrict your results, use rphonebook: for residential listings or bphonebook: for business listings. If you'd rather use a search form for business phone listings, try Yellow Search
(www.buzztoolbox.com/google/yellowsearch.shtml).
Extended Googling
Google offers several services that give you a head start in focusing your search. Google Groups
(http://groups.google.com/)
indexes literally millions of messages from decades of discussion on Usenet. Google even helps you with your shopping via two tools: Froogle
CODE
(http://froogle.google.com/),
which indexes products from online stores, and Google Catalogs
CODE
(http://catalogs.google.com/),
which features products from more 6,000 paper catalogs in a searchable index. And this only scratches the surface. You can get a complete list of Google's tools and services at
www.google.com/options/index.html
You're probably used to using Google in your browser. But have you ever thought of using Google outside your browser?
Google Alert
(http://www.googlealert.com/)
monitors your search terms and e-mails you information about new additions to Google's Web index. (Google Alert is not affiliated with Google; it uses Google's Web services API to perform its searches.) If you're more interested in news stories than general Web content, check out the beta version of Google News Alerts
(www.google.com/newsalerts).
This service (which is affiliated with Google) will monitor up to 50 news queries per e-mail address and send you information about news stories that match your query. (Hint: Use the intitle: and source: syntax elements with Google News to limit the number of alerts you get.)
Google on the telephone? Yup. This service is brought to you by the folks at Google Labs
(http://labs.google.com/),
a place for experimental Google ideas and features (which may come and go, so what's there at this writing might not be there when you decide to check it out). With Google Voice Search
(http://labs1.google.com/gvs.html),
you dial the Voice Search phone number, speak your keywords, and then click on the indicated link. Every time you say a new search term, the results page will refresh with your new query (you must have JavaScript enabled for this to work). Remember, this service is still in an experimental phase, so don't expect 100 percent success.
In 2002, Google released the Google API (application programming interface), a way for programmers to access Google's search engine results without violating the Google Terms of Service. A lot of people have created useful (and occasionally not-so-useful but interesting) applications not available from Google itself, such as Google Alert. For many applications, you'll need an API key, which is available free from
CODE
www.google.com/apis
. See the figures for two more examples, and visit
www.pcmag.com/solutions
for more.
Thanks to its many different search properties, Google goes far beyond a regular search engine. Give the tricks in this article a try. You'll be amazed at how many different ways Google can improve your Internet searching.
Online Extra: More Google Tips
Here are a few more clever ways to tweak your Google searches.
Search Within a Timeframe
Daterange: (start date–end date). You can restrict your searches to pages that were indexed within a certain time period. Daterange: searches by when Google indexed a page, not when the page itself was created. This operator can help you ensure that results will have fresh content (by using recent dates), or you can use it to avoid a topic's current-news blizzard and concentrate only on older results. Daterange: is actually more useful if you go elsewhere to take advantage of it, because daterange: requires Julian dates, not standard Gregorian dates. You can find converters on the Web (such as
CODE
http://aa.usno.navy.mil/data/docs/JulianDate.html
excl.gif No Active Links, Read the Rules - Edit by Ninja excl.gif
), but an easier way is to do a Google daterange: search by filling in a form at
www.researchbuzz.com/toolbox/goofresh.shtml or www.faganfinder.com/engines/google.shtml
. If one special syntax element is good, two must be better, right? Sometimes. Though some operators can't be mixed (you can't use the link: operator with anything else) many can be, quickly narrowing your results to a less overwhelming number.
More Google API Applications
Staggernation.com offers three tools based on the Google API. The Google API Web Search by Host (GAWSH) lists the Web hosts of the results for a given query
(www.staggernation.com/gawsh/).
When you click on the triangle next to each host, you get a list of results for that host. The Google API Relation Browsing Outliner (GARBO) is a little more complicated: You enter a URL and choose whether you want pages that related to the URL or linked to the URL
(www.staggernation.com/garbo/).
Click on the triangle next to an URL to get a list of pages linked or related to that particular URL. CapeMail is an e-mail search application that allows you to send an e-mail to google@capeclear.com with the text of your query in the subject line and get the first ten results for that query back. Maybe it's not something you'd do every day, but if your cell phone does e-mail and doesn't do Web browsing, this is a very handy address to know.
excl.gif No Active Links, Read the Rules - Edit by Ninja excl.gif
Google is clearly the best general-purpose search engine on the Web (see
www.pcmag.com/searchengines
But most people don't use it to its best advantage. Do you just plug in a keyword or two and hope for the best? That may be the quickest way to search, but with more than 3 billion pages in Google's index, it's still a struggle to pare results to a manageable number.
But Google is an remarkably powerful tool that can ease and enhance your Internet exploration. Google's search options go beyond simple keywords, the Web, and even its own programmers. Let's look at some of Google's lesser-known options.
Syntax Search Tricks
Using a special syntax is a way to tell Google that you want to restrict your searches to certain elements or characteristics of Web pages. Google has a fairly complete list of its syntax elements at
www.google.com/help/operators.html
. Here are some advanced operators that can help narrow down your search results.
Intitle: at the beginning of a query word or phrase (intitle:"Three Blind Mice") restricts your search results to just the titles of Web pages.
Intext: does the opposite of intitle:, searching only the body text, ignoring titles, links, and so forth. Intext: is perfect when what you're searching for might commonly appear in URLs. If you're looking for the term HTML, for example, and you don't want to get results such as
www.mysite.com/index.html
, you can enter intext:html.
Link: lets you see which pages are linking to your Web page or to another page you're interested in. For example, try typing in
link:http://www.pcmag.com
Try using site: (which restricts results to top-level domains) with intitle: to find certain types of pages. For example, get scholarly pages about Mark Twain by searching for intitle:"Mark Twain"site:edu. Experiment with mixing various elements; you'll develop several strategies for finding the stuff you want more effectively. The site: command is very helpful as an alternative to the mediocre search engines built into many sites.
Swiss Army Google
Google has a number of services that can help you accomplish tasks you may never have thought to use Google for. For example, the new calculator feature
(www.google.com/help/features.html#calculator)
lets you do both math and a variety of conversions from the search box. For extra fun, try the query "Answer to life the universe and everything."
Let Google help you figure out whether you've got the right spelling—and the right word—for your search. Enter a misspelled word or phrase into the query box (try "thre blund mise") and Google may suggest a proper spelling. This doesn't always succeed; it works best when the word you're searching for can be found in a dictionary. Once you search for a properly spelled word, look at the results page, which repeats your query. (If you're searching for "three blind mice," underneath the search window will appear a statement such as Searched the web for "three blind mice.") You'll discover that you can click on each word in your search phrase and get a definition from a dictionary.
Suppose you want to contact someone and don't have his phone number handy. Google can help you with that, too. Just enter a name, city, and state. (The city is optional, but you must enter a state.) If a phone number matches the listing, you'll see it at the top of the search results along with a map link to the address. If you'd rather restrict your results, use rphonebook: for residential listings or bphonebook: for business listings. If you'd rather use a search form for business phone listings, try Yellow Search
(www.buzztoolbox.com/google/yellowsearch.shtml).
Extended Googling
Google offers several services that give you a head start in focusing your search. Google Groups
(http://groups.google.com/)
indexes literally millions of messages from decades of discussion on Usenet. Google even helps you with your shopping via two tools: Froogle
CODE
(http://froogle.google.com/),
which indexes products from online stores, and Google Catalogs
CODE
(http://catalogs.google.com/),
which features products from more 6,000 paper catalogs in a searchable index. And this only scratches the surface. You can get a complete list of Google's tools and services at
www.google.com/options/index.html
You're probably used to using Google in your browser. But have you ever thought of using Google outside your browser?
Google Alert
(http://www.googlealert.com/)
monitors your search terms and e-mails you information about new additions to Google's Web index. (Google Alert is not affiliated with Google; it uses Google's Web services API to perform its searches.) If you're more interested in news stories than general Web content, check out the beta version of Google News Alerts
(www.google.com/newsalerts).
This service (which is affiliated with Google) will monitor up to 50 news queries per e-mail address and send you information about news stories that match your query. (Hint: Use the intitle: and source: syntax elements with Google News to limit the number of alerts you get.)
Google on the telephone? Yup. This service is brought to you by the folks at Google Labs
(http://labs.google.com/),
a place for experimental Google ideas and features (which may come and go, so what's there at this writing might not be there when you decide to check it out). With Google Voice Search
(http://labs1.google.com/gvs.html),
you dial the Voice Search phone number, speak your keywords, and then click on the indicated link. Every time you say a new search term, the results page will refresh with your new query (you must have JavaScript enabled for this to work). Remember, this service is still in an experimental phase, so don't expect 100 percent success.
In 2002, Google released the Google API (application programming interface), a way for programmers to access Google's search engine results without violating the Google Terms of Service. A lot of people have created useful (and occasionally not-so-useful but interesting) applications not available from Google itself, such as Google Alert. For many applications, you'll need an API key, which is available free from
CODE
www.google.com/apis
. See the figures for two more examples, and visit
www.pcmag.com/solutions
for more.
Thanks to its many different search properties, Google goes far beyond a regular search engine. Give the tricks in this article a try. You'll be amazed at how many different ways Google can improve your Internet searching.
Online Extra: More Google Tips
Here are a few more clever ways to tweak your Google searches.
Search Within a Timeframe
Daterange: (start date–end date). You can restrict your searches to pages that were indexed within a certain time period. Daterange: searches by when Google indexed a page, not when the page itself was created. This operator can help you ensure that results will have fresh content (by using recent dates), or you can use it to avoid a topic's current-news blizzard and concentrate only on older results. Daterange: is actually more useful if you go elsewhere to take advantage of it, because daterange: requires Julian dates, not standard Gregorian dates. You can find converters on the Web (such as
CODE
http://aa.usno.navy.mil/data/docs/JulianDate.html
excl.gif No Active Links, Read the Rules - Edit by Ninja excl.gif
), but an easier way is to do a Google daterange: search by filling in a form at
www.researchbuzz.com/toolbox/goofresh.shtml or www.faganfinder.com/engines/google.shtml
. If one special syntax element is good, two must be better, right? Sometimes. Though some operators can't be mixed (you can't use the link: operator with anything else) many can be, quickly narrowing your results to a less overwhelming number.
More Google API Applications
Staggernation.com offers three tools based on the Google API. The Google API Web Search by Host (GAWSH) lists the Web hosts of the results for a given query
(www.staggernation.com/gawsh/).
When you click on the triangle next to each host, you get a list of results for that host. The Google API Relation Browsing Outliner (GARBO) is a little more complicated: You enter a URL and choose whether you want pages that related to the URL or linked to the URL
(www.staggernation.com/garbo/).
Click on the triangle next to an URL to get a list of pages linked or related to that particular URL. CapeMail is an e-mail search application that allows you to send an e-mail to google@capeclear.com with the text of your query in the subject line and get the first ten results for that query back. Maybe it's not something you'd do every day, but if your cell phone does e-mail and doesn't do Web browsing, this is a very handy address to know.
10 Fast and Free Security Enhancements
Before you spend a dime on security, there are many precautions you can take that will protect you against the most common threats.
1. Check Windows Update and Office Update regularly (_http://office.microsoft.com/productupdates); have your Office CD ready. Windows Me, 2000, and XP users can configure automatic updates. Click on the Automatic Updates tab in the System control panel and choose the appropriate options.
2. Install a personal firewall. Both SyGate (_www.sygate.com) and ZoneAlarm (_www.zonelabs.com) offer free versions.
3. Install a free spyware blocker. Our Editors' Choice ("Spyware," April 22) was SpyBot Search & Destroy (_http://security.kolla.de). SpyBot is also paranoid and ruthless in hunting out tracking cookies.
4. Block pop-up spam messages in Windows NT, 2000, or XP by disabling the Windows Messenger service (this is unrelated to the instant messaging program). Open Control Panel | Administrative Tools | Services and you'll see Messenger. Right-click and go to Properties. Set Start-up Type to Disabled and press the Stop button. Bye-bye, spam pop-ups! Any good firewall will also stop them.
5. Use strong passwords and change them periodically. Passwords should have at least seven characters; use letters and numbers and have at least one symbol. A decent example would be f8izKro@l. This will make it much harder for anyone to gain access to your accounts.
6. If you're using Outlook or Outlook Express, use the current version or one with the Outlook Security Update installed. The update and current versions patch numerous vulnerabilities.
7. Buy antivirus software and keep it up to date. If you're not willing to pay, try Grisoft AVG Free Edition (Grisoft Inc., w*w.grisoft.com). And doublecheck your AV with the free, online-only scanners available at w*w.pandasoftware.com/activescan and _http://housecall.trendmicro.com.
8. If you have a wireless network, turn on the security features: Use MAC filtering, turn off SSID broadcast, and even use WEP with the biggest key you can get. For more, check out our wireless section or see the expanded coverage in Your Unwired World in our next issue.
9. Join a respectable e-mail security list, such as the one found at our own Security Supersite at _http://security.ziffdavis.com, so that you learn about emerging threats quickly and can take proper precautions.
10. Be skeptical of things on the Internet. Don't assume that e-mail "From:" a particular person is actually from that person until you have further reason to believe it's that person. Don't assume that an attachment is what it says it is. Don't give out your password to anyone, even if that person claims to be from "support."
1. Check Windows Update and Office Update regularly (_http://office.microsoft.com/productupdates); have your Office CD ready. Windows Me, 2000, and XP users can configure automatic updates. Click on the Automatic Updates tab in the System control panel and choose the appropriate options.
2. Install a personal firewall. Both SyGate (_www.sygate.com) and ZoneAlarm (_www.zonelabs.com) offer free versions.
3. Install a free spyware blocker. Our Editors' Choice ("Spyware," April 22) was SpyBot Search & Destroy (_http://security.kolla.de). SpyBot is also paranoid and ruthless in hunting out tracking cookies.
4. Block pop-up spam messages in Windows NT, 2000, or XP by disabling the Windows Messenger service (this is unrelated to the instant messaging program). Open Control Panel | Administrative Tools | Services and you'll see Messenger. Right-click and go to Properties. Set Start-up Type to Disabled and press the Stop button. Bye-bye, spam pop-ups! Any good firewall will also stop them.
5. Use strong passwords and change them periodically. Passwords should have at least seven characters; use letters and numbers and have at least one symbol. A decent example would be f8izKro@l. This will make it much harder for anyone to gain access to your accounts.
6. If you're using Outlook or Outlook Express, use the current version or one with the Outlook Security Update installed. The update and current versions patch numerous vulnerabilities.
7. Buy antivirus software and keep it up to date. If you're not willing to pay, try Grisoft AVG Free Edition (Grisoft Inc., w*w.grisoft.com). And doublecheck your AV with the free, online-only scanners available at w*w.pandasoftware.com/activescan and _http://housecall.trendmicro.com.
8. If you have a wireless network, turn on the security features: Use MAC filtering, turn off SSID broadcast, and even use WEP with the biggest key you can get. For more, check out our wireless section or see the expanded coverage in Your Unwired World in our next issue.
9. Join a respectable e-mail security list, such as the one found at our own Security Supersite at _http://security.ziffdavis.com, so that you learn about emerging threats quickly and can take proper precautions.
10. Be skeptical of things on the Internet. Don't assume that e-mail "From:" a particular person is actually from that person until you have further reason to believe it's that person. Don't assume that an attachment is what it says it is. Don't give out your password to anyone, even if that person claims to be from "support."
Sunday, October 10, 2010
10 reasons why PCs crash U must Know
Fatal error: the system has become unstable or is busy," it says. "Enter to return to Windows or press Control-Alt-Delete to restart your computer. If you do this you will lose any unsaved information in all open applications."
You have just been struck by the Blue Screen of Death. Anyone who uses Mcft Windows will be familiar with this. What can you do? More importantly, how can you prevent it happening?
1 Hardware conflict
The number one reason why Windows crashes is hardware conflict. Each hardware device communicates to other devices through an interrupt request channel (IRQ). These are supposed to be unique for each device.
For example, a printer usually connects internally on IRQ 7. The keyboard usually uses IRQ 1 and the floppy disk drive IRQ 6. Each device will try to hog a single IRQ for itself.
If there are a lot of devices, or if they are not installed properly, two of them may end up sharing the same IRQ number. When the user tries to use both devices at the same time, a crash can happen. The way to check if your computer has a hardware conflict is through the following route:
* Start-Settings-Control Panel-System-Device Manager.
Often if a device has a problem a yellow '!' appears next to its description in the Device Manager. Highlight Computer (in the Device Manager) and press Properties to see the IRQ numbers used by your computer. If the IRQ number appears twice, two devices may be using it.
Sometimes a device might share an IRQ with something described as 'IRQ holder for PCI steering'. This can be ignored. The best way to fix this problem is to remove the problem device and reinstall it.
Sometimes you may have to find more recent drivers on the internet to make the device function properly. A good resource is http://www.driverguide.com/. If the device is a soundcard, or a modem, it can often be fixed by moving it to a different slot on the motherboard (be careful about opening your computer, as you may void the warranty).
When working inside a computer you should switch it off, unplug the mains lead and touch an unpainted metal surface to discharge any static electricity.
To be fair to Mcft, the problem with IRQ numbers is not of its making. It is a legacy problem going back to the first PC designs using the IBM 8086 chip. Initially there were only eight IRQs. Today there are 16 IRQs in a PC. It is easy to run out of them. There are plans to increase the number of IRQs in future designs.
2 Bad Ram
Ram (random-access memory) problems might bring on the blue screen of death with a message saying Fatal Exception Error. A fatal error indicates a serious hardware problem. Sometimes it may mean a part is damaged and will need replacing.
But a fatal error caused by Ram might be caused by a mismatch of chips. For example, mixing 70-nanosecond (70ns) Ram with 60ns Ram will usually force the computer to run all the Ram at the slower speed. This will often crash the machine if the Ram is overworked.
One way around this problem is to enter the BIOS settings and increase the wait state of the Ram. This can make it more stable. Another way to troubleshoot a suspected Ram problem is to rearrange the Ram chips on the motherboard, or take some of them out. Then try to repeat the circumstances that caused the crash. When handling Ram try not to touch the gold connections, as they can be easily damaged.
Parity error messages also refer to Ram. Modern Ram chips are either parity (ECC) or non parity (non-ECC). It is best not to mix the two types, as this can be a cause of trouble.
EMM386 error messages refer to memory problems but may not be connected to bad Ram. This may be due to free memory problems often linked to old Dos-based programmes.
3 BIOS settings
Every motherboard is supplied with a range of chipset settings that are decided in the factory. A common way to access these settings is to press the F2 or delete button during the first few seconds of a boot-up.
Once inside the BIOS, great care should be taken. It is a good idea to write down on a piece of paper all the settings that appear on the screen. That way, if you change something and the computer becomes more unstable, you will know what settings to revert to.
A common BIOS error concerns the CAS latency. This refers to the Ram. Older EDO (extended data out) Ram has a CAS latency of 3. Newer SDRam has a CAS latency of 2. Setting the wrong figure can cause the Ram to lock up and freeze the computer's display.
Mcft Windows is better at allocating IRQ numbers than any BIOS. If possible set the IRQ numbers to Auto in the BIOS. This will allow Windows to allocate the IRQ numbers (make sure the BIOS setting for Plug and Play OS is switched to 'yes' to allow Windows to do this.).
4 Hard disk drives
After a few weeks, the information on a hard disk drive starts to become piecemeal or fragmented. It is a good idea to defragment the hard disk every week or so, to prevent the disk from causing a screen freeze. Go to
* Start-Programs-Accessories-System Tools-Disk Defragmenter
This will start the procedure. You will be unable to write data to the hard drive (to save it) while the disk is defragmenting, so it is a good idea to schedule the procedure for a period of inactivity using the Task Scheduler.
The Task Scheduler should be one of the small icons on the bottom right of the Windows opening page (the desktop).
Some lockups and screen freezes caused by hard disk problems can be solved by reducing the read-ahead optimisation. This can be adjusted by going to
* Start-Settings-Control Panel-System Icon-Performance-File System-Hard Disk.
Hard disks will slow down and crash if they are too full. Do some housekeeping on your hard drive every few months and free some space on it. Open the Windows folder on the C drive and find the Temporary Internet Files folder. Deleting the contents (not the folder) can free a lot of space.
Empty the Recycle Bin every week to free more space. Hard disk drives should be scanned every week for errors or bad sectors. Go to
* Start-Programs-Accessories-System Tools-ScanDisk
Otherwise assign the Task Scheduler to perform this operation at night when the computer is not in use.
5 Fatal OE exceptions and VXD errors
Fatal OE exception errors and VXD errors are often caused by video card problems.
These can often be resolved easily by reducing the resolution of the video display. Go to
* Start-Settings-Control Panel-Display-Settings
Here you should slide the screen area bar to the left. Take a look at the colour settings on the left of that window. For most desktops, high colour 16-bit depth is adequate.
If the screen freezes or you experience system lockups it might be due to the video card. Make sure it does not have a hardware conflict. Go to
* Start-Settings-Control Panel-System-Device Manager
Here, select the + beside Display Adapter. A line of text describing your video card should appear. Select it (make it blue) and press properties. Then select Resources and select each line in the window. Look for a message that says No Conflicts.
If you have video card hardware conflict, you will see it here. Be careful at this point and make a note of everything you do in case you make things worse.
The way to resolve a hardware conflict is to uncheck the Use Automatic Settings box and hit the Change Settings button. You are searching for a setting that will display a No Conflicts message.
Another useful way to resolve video problems is to go to
* Start-Settings-Control Panel-System-Performance-Graphics
Here you should move the Hardware Acceleration slider to the left. As ever, the most common cause of problems relating to graphics cards is old or faulty drivers (a driver is a small piece of software used by a computer to communicate with a device).
Look up your video card's manufacturer on the internet and search for the most recent drivers for it.
6 Viruses
Often the first sign of a virus infection is instability. Some viruses erase the boot sector of a hard drive, making it impossible to start. This is why it is a good idea to create a Windows start-up disk. Go to
* Start-Settings-Control Panel-Add/Remove Programs
Here, look for the Start Up Disk tab. Virus protection requires constant vigilance.
A virus scanner requires a list of virus signatures in order to be able to identify viruses. These signatures are stored in a DAT file. DAT files should be updated weekly from the website of your antivirus software manufacturer.
An excellent antivirus programme is McAfee VirusScan by Network Associates ( http://www.nai.com/). Another is Norton AntiVirus 2000, made by Symantec ( http://www.symantec.com/).
7 Printers
The action of sending a document to print creates a bigger file, often called a postscript file.
Printers have only a small amount of memory, called a buffer. This can be easily overloaded. Printing a document also uses a considerable amount of CPU power. This will also slow down the computer's performance.
If the printer is trying to print unusual characters, these might not be recognised, and can crash the computer. Sometimes printers will not recover from a crash because of confusion in the buffer. A good way to clear the buffer is to unplug the printer for ten seconds. Booting up from a powerless state, also called a cold boot, will restore the printer's default settings and you may be able to carry on.
8 Software
A common cause of computer crash is faulty or badly-installed software. Often the problem can be cured by uninstalling the software and then reinstalling it. Use Norton Uninstall or Uninstall Shield to remove an application from your system properly. This will also remove references to the programme in the System Registry and leaves the way clear for a completely fresh copy.
The System Registry can be corrupted by old references to obsolete software that you thought was uninstalled. Use Reg Cleaner by Jouni Vuorio to clean up the System Registry and remove obsolete entries. It works on Windows 95, Windows 98, Windows 98 SE (Second Edition), Windows Millennium Edition (ME), NT4 and Windows 2000.
Read the instructions and use it carefully so you don't do permanent damage to the Registry. If the Registry is damaged you will have to reinstall your operating system. Reg Cleaner can be obtained from http://www.jv16.org/
Often a Windows problem can be resolved by entering Safe Mode. This can be done during start-up. When you see the message "Starting Windows" press F4. This should take you into Safe Mode.
Safe Mode loads a minimum of drivers. It allows you to find and fix problems that prevent Windows from loading properly.
Sometimes installing Windows is difficult because of unsuitable BIOS settings. If you keep getting SUWIN error messages (Windows setup) during the Windows installation, then try entering the BIOS and disabling the CPU internal cache. Try to disable the Level 2 (L2) cache if that doesn't work.
Remember to restore all the BIOS settings back to their former settings following installation.
9 Overheating
Central processing units (CPUs) are usually equipped with fans to keep them cool. If the fan fails or if the CPU gets old it may start to overheat and generate a particular kind of error called a kernel error. This is a common problem in chips that have been overclocked to operate at higher speeds than they are supposed to.
One remedy is to get a bigger better fan and install it on top of the CPU. Specialist cooling fans/heatsinks are available from http://www.computernerd.com/ or http://www.coolit.com/
CPU problems can often be fixed by disabling the CPU internal cache in the BIOS. This will make the machine run more slowly, but it should also be more stable.
10 Power supply problems
With all the new construction going on around the country the steady supply of electricity has become disrupted. A power surge or spike can crash a computer as easily as a power cut.
If this has become a nuisance for you then consider buying a uninterrupted power supply (UPS). This will give you a clean power supply when there is electricity, and it will give you a few minutes to perform a controlled shutdown in case of a power cut.
It is a good investment if your data are critical, because a power cut will cause any unsaved data to be lost.
You have just been struck by the Blue Screen of Death. Anyone who uses Mcft Windows will be familiar with this. What can you do? More importantly, how can you prevent it happening?
1 Hardware conflict
The number one reason why Windows crashes is hardware conflict. Each hardware device communicates to other devices through an interrupt request channel (IRQ). These are supposed to be unique for each device.
For example, a printer usually connects internally on IRQ 7. The keyboard usually uses IRQ 1 and the floppy disk drive IRQ 6. Each device will try to hog a single IRQ for itself.
If there are a lot of devices, or if they are not installed properly, two of them may end up sharing the same IRQ number. When the user tries to use both devices at the same time, a crash can happen. The way to check if your computer has a hardware conflict is through the following route:
* Start-Settings-Control Panel-System-Device Manager.
Often if a device has a problem a yellow '!' appears next to its description in the Device Manager. Highlight Computer (in the Device Manager) and press Properties to see the IRQ numbers used by your computer. If the IRQ number appears twice, two devices may be using it.
Sometimes a device might share an IRQ with something described as 'IRQ holder for PCI steering'. This can be ignored. The best way to fix this problem is to remove the problem device and reinstall it.
Sometimes you may have to find more recent drivers on the internet to make the device function properly. A good resource is http://www.driverguide.com/. If the device is a soundcard, or a modem, it can often be fixed by moving it to a different slot on the motherboard (be careful about opening your computer, as you may void the warranty).
When working inside a computer you should switch it off, unplug the mains lead and touch an unpainted metal surface to discharge any static electricity.
To be fair to Mcft, the problem with IRQ numbers is not of its making. It is a legacy problem going back to the first PC designs using the IBM 8086 chip. Initially there were only eight IRQs. Today there are 16 IRQs in a PC. It is easy to run out of them. There are plans to increase the number of IRQs in future designs.
2 Bad Ram
Ram (random-access memory) problems might bring on the blue screen of death with a message saying Fatal Exception Error. A fatal error indicates a serious hardware problem. Sometimes it may mean a part is damaged and will need replacing.
But a fatal error caused by Ram might be caused by a mismatch of chips. For example, mixing 70-nanosecond (70ns) Ram with 60ns Ram will usually force the computer to run all the Ram at the slower speed. This will often crash the machine if the Ram is overworked.
One way around this problem is to enter the BIOS settings and increase the wait state of the Ram. This can make it more stable. Another way to troubleshoot a suspected Ram problem is to rearrange the Ram chips on the motherboard, or take some of them out. Then try to repeat the circumstances that caused the crash. When handling Ram try not to touch the gold connections, as they can be easily damaged.
Parity error messages also refer to Ram. Modern Ram chips are either parity (ECC) or non parity (non-ECC). It is best not to mix the two types, as this can be a cause of trouble.
EMM386 error messages refer to memory problems but may not be connected to bad Ram. This may be due to free memory problems often linked to old Dos-based programmes.
3 BIOS settings
Every motherboard is supplied with a range of chipset settings that are decided in the factory. A common way to access these settings is to press the F2 or delete button during the first few seconds of a boot-up.
Once inside the BIOS, great care should be taken. It is a good idea to write down on a piece of paper all the settings that appear on the screen. That way, if you change something and the computer becomes more unstable, you will know what settings to revert to.
A common BIOS error concerns the CAS latency. This refers to the Ram. Older EDO (extended data out) Ram has a CAS latency of 3. Newer SDRam has a CAS latency of 2. Setting the wrong figure can cause the Ram to lock up and freeze the computer's display.
Mcft Windows is better at allocating IRQ numbers than any BIOS. If possible set the IRQ numbers to Auto in the BIOS. This will allow Windows to allocate the IRQ numbers (make sure the BIOS setting for Plug and Play OS is switched to 'yes' to allow Windows to do this.).
4 Hard disk drives
After a few weeks, the information on a hard disk drive starts to become piecemeal or fragmented. It is a good idea to defragment the hard disk every week or so, to prevent the disk from causing a screen freeze. Go to
* Start-Programs-Accessories-System Tools-Disk Defragmenter
This will start the procedure. You will be unable to write data to the hard drive (to save it) while the disk is defragmenting, so it is a good idea to schedule the procedure for a period of inactivity using the Task Scheduler.
The Task Scheduler should be one of the small icons on the bottom right of the Windows opening page (the desktop).
Some lockups and screen freezes caused by hard disk problems can be solved by reducing the read-ahead optimisation. This can be adjusted by going to
* Start-Settings-Control Panel-System Icon-Performance-File System-Hard Disk.
Hard disks will slow down and crash if they are too full. Do some housekeeping on your hard drive every few months and free some space on it. Open the Windows folder on the C drive and find the Temporary Internet Files folder. Deleting the contents (not the folder) can free a lot of space.
Empty the Recycle Bin every week to free more space. Hard disk drives should be scanned every week for errors or bad sectors. Go to
* Start-Programs-Accessories-System Tools-ScanDisk
Otherwise assign the Task Scheduler to perform this operation at night when the computer is not in use.
5 Fatal OE exceptions and VXD errors
Fatal OE exception errors and VXD errors are often caused by video card problems.
These can often be resolved easily by reducing the resolution of the video display. Go to
* Start-Settings-Control Panel-Display-Settings
Here you should slide the screen area bar to the left. Take a look at the colour settings on the left of that window. For most desktops, high colour 16-bit depth is adequate.
If the screen freezes or you experience system lockups it might be due to the video card. Make sure it does not have a hardware conflict. Go to
* Start-Settings-Control Panel-System-Device Manager
Here, select the + beside Display Adapter. A line of text describing your video card should appear. Select it (make it blue) and press properties. Then select Resources and select each line in the window. Look for a message that says No Conflicts.
If you have video card hardware conflict, you will see it here. Be careful at this point and make a note of everything you do in case you make things worse.
The way to resolve a hardware conflict is to uncheck the Use Automatic Settings box and hit the Change Settings button. You are searching for a setting that will display a No Conflicts message.
Another useful way to resolve video problems is to go to
* Start-Settings-Control Panel-System-Performance-Graphics
Here you should move the Hardware Acceleration slider to the left. As ever, the most common cause of problems relating to graphics cards is old or faulty drivers (a driver is a small piece of software used by a computer to communicate with a device).
Look up your video card's manufacturer on the internet and search for the most recent drivers for it.
6 Viruses
Often the first sign of a virus infection is instability. Some viruses erase the boot sector of a hard drive, making it impossible to start. This is why it is a good idea to create a Windows start-up disk. Go to
* Start-Settings-Control Panel-Add/Remove Programs
Here, look for the Start Up Disk tab. Virus protection requires constant vigilance.
A virus scanner requires a list of virus signatures in order to be able to identify viruses. These signatures are stored in a DAT file. DAT files should be updated weekly from the website of your antivirus software manufacturer.
An excellent antivirus programme is McAfee VirusScan by Network Associates ( http://www.nai.com/). Another is Norton AntiVirus 2000, made by Symantec ( http://www.symantec.com/).
7 Printers
The action of sending a document to print creates a bigger file, often called a postscript file.
Printers have only a small amount of memory, called a buffer. This can be easily overloaded. Printing a document also uses a considerable amount of CPU power. This will also slow down the computer's performance.
If the printer is trying to print unusual characters, these might not be recognised, and can crash the computer. Sometimes printers will not recover from a crash because of confusion in the buffer. A good way to clear the buffer is to unplug the printer for ten seconds. Booting up from a powerless state, also called a cold boot, will restore the printer's default settings and you may be able to carry on.
8 Software
A common cause of computer crash is faulty or badly-installed software. Often the problem can be cured by uninstalling the software and then reinstalling it. Use Norton Uninstall or Uninstall Shield to remove an application from your system properly. This will also remove references to the programme in the System Registry and leaves the way clear for a completely fresh copy.
The System Registry can be corrupted by old references to obsolete software that you thought was uninstalled. Use Reg Cleaner by Jouni Vuorio to clean up the System Registry and remove obsolete entries. It works on Windows 95, Windows 98, Windows 98 SE (Second Edition), Windows Millennium Edition (ME), NT4 and Windows 2000.
Read the instructions and use it carefully so you don't do permanent damage to the Registry. If the Registry is damaged you will have to reinstall your operating system. Reg Cleaner can be obtained from http://www.jv16.org/
Often a Windows problem can be resolved by entering Safe Mode. This can be done during start-up. When you see the message "Starting Windows" press F4. This should take you into Safe Mode.
Safe Mode loads a minimum of drivers. It allows you to find and fix problems that prevent Windows from loading properly.
Sometimes installing Windows is difficult because of unsuitable BIOS settings. If you keep getting SUWIN error messages (Windows setup) during the Windows installation, then try entering the BIOS and disabling the CPU internal cache. Try to disable the Level 2 (L2) cache if that doesn't work.
Remember to restore all the BIOS settings back to their former settings following installation.
9 Overheating
Central processing units (CPUs) are usually equipped with fans to keep them cool. If the fan fails or if the CPU gets old it may start to overheat and generate a particular kind of error called a kernel error. This is a common problem in chips that have been overclocked to operate at higher speeds than they are supposed to.
One remedy is to get a bigger better fan and install it on top of the CPU. Specialist cooling fans/heatsinks are available from http://www.computernerd.com/ or http://www.coolit.com/
CPU problems can often be fixed by disabling the CPU internal cache in the BIOS. This will make the machine run more slowly, but it should also be more stable.
10 Power supply problems
With all the new construction going on around the country the steady supply of electricity has become disrupted. A power surge or spike can crash a computer as easily as a power cut.
If this has become a nuisance for you then consider buying a uninterrupted power supply (UPS). This will give you a clean power supply when there is electricity, and it will give you a few minutes to perform a controlled shutdown in case of a power cut.
It is a good investment if your data are critical, because a power cut will cause any unsaved data to be lost.
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