binaya's Blog
Category computer
Sorry, but the blog post could not be located.  E-learning, falls, into, four, categories, from, the, very, basic, to, the, very, advanced., The, categories, are:, Sorry, but the blog post could not be located. Turn, off, the, feature, that, allows, automatic, opening, of, email, attachments, never, open, attachments, from, unidentified, sources, or, attachments, you, are, not, expecting.,
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i) Use virus protection software: We recommend the use of anti-virus software on all Internet-connected computers. Be sure to keep your anti-virus software up-to-date. Many anti-virus packages support automatic updates of virus definitions. We recommend the use of these automatic updates when available. ii) Use a firewall: We strongly recommend the use of some type of firewall product, such as a network appliance or a personal firewall software package. Intruders are constantly scanning home user systems for known vulnerabilities. Network firewalls (whether software or hardware-based) can provide some degree of protection against these attacks. However, no firewall can detect or stop all attacks, so it’s not sufficient to install a firewall and then ignore all other security measures.
iii) Don’t open unknown email attachments: Before opening any email attachments, be sure you know the source of the attachment. It is not enough that the mail originated from an address you recognize. The Melissa virus spread precisely because it originated from a familiar address. Malicious code might be distributed in amusing or enticing programs.
If you must open an attachment before you can verify the source, we suggest the following procedure: make sure your virus definitions are up-to-date (see "Use virus protection software" above)
save the file to your hard disk
scan the file using your antivirus software
open the file
For additional protection, you can disconnect your computer's network connection before opening the file. Following these steps will reduce, but not wholly eliminate, the chance that any malicious code contained in the attachment might spread from your computer to others. iv) Don’t run programs of unknown origin: Never run a program unless you know it to be authored by a person or company that you trust. Also, don't send programs of unknown origin to your friends or coworkers simply because they are amusing -- they might contain a Trojan horse program.
v) Keep all applications (including your operating system) patched: Vendors will usually release patches for their software when a vulnerability has been discovered. Most product documentation offers a method to get updates and patches. You should be able to obtain updates from the vendor's web site. Read the manuals or browse the vendor's web site for more information. Some applications will automatically check for available updates, and many vendors offer automatic notification of updates via a mailing list. Look on your vendor's web site for information about automatic notification. If no mailing list or other automated notification mechanism is offered you may need to check periodically for updates. vi) Make regular backups of critical data: Keep a copy of important files on removable media such as ZIP disks or recordable CD-ROM disks (CD-R or CD-RW disks). Use software backup tools if available, and store the backup disks somewhere away from the computer. vii) Disable scripting features in email programs: Because many email programs use the same code as web browsers to display HTML, vulnerabilities that affect ActiveX, Java, and JavaScript are often applicable to email as well as web pages. Therefore, in addition to disabling scripting features in web browsers (see "Disable Java, JavaScript, and ActiveX if possible", above), we recommend that users also disable these features in their email programs. viii) Turn off your computer or disconnect from the network when not in use: Turn off your computer or disconnect its Ethernet interface when you are not using it. An intruder cannot attack your computer if it is powered off or otherwise completely disconnected from the network. worldlink.com.np http://homejob.justfree.com some adsense tips i), Use, virus, protection, software:, We, recommend, the, use, of, anti-virus, software, on, all, Internet-connected, computers., Be, sure, to, keep, your, anti-virus, software, up-to-date., Many, anti-virus, packages, support, automatic, updates, of, virus, definitions., We, r
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| The motherboard has been an integral part of most personal computers for more than 20 years. Think of a motherboard as a scale model of a futuristic city with many modular plug-in buildings, each using power from a common electrical system. Multiple-lane highways of various widths transport data between the buildings. The motherboard is the data and power infrastructure for the entire computer. Motherboards (also called mainboards) are actually a carryover from architecture used for years in mainframe computers. Various circuit cards performing various functions all plug into many similar sockets on a common circuit board. Each circuit card performs a unique function in the computer and gets its power from the socket as well. Due to improvements in circuitry and packaging, motherboards have essentially stayed the same size or shrunk (in square inches), while their functionality has skyrocketed in the past 20 years. In this edition of Stuff.dewsoftoverseas.com, you will learn more about how the motherboard works, and about a motherboard's many sockets and connectors.  A Brief History
The original IBM PC contained the original PC motherboard. In this design, which premiered in 1982, the motherboard itself was a large printed circuit card that contained the 8088 microprocessor, the BIOS, sockets for the CPU's RAM and a collection of slots that auxiliary cards could plug into. If you wanted to add a floppy disk drive or a parallel port or a joy stick, you bought a separate card and plugged it into one of the slots. This approach was originally pioneered in the mass market by the Apple II machine. By making it easy to add cards, Apple and IBM accomplished two things:
- They made it easy to add new features to the machine over time
- They opened the computer to creative opportunities by third-party vendors
Motherboard Sizes
Different motherboards of different vintages typically have different form factors. Form factor essentially means the size and shape of the actual motherboard. There are more than a half-dozen form factors for motherboards, with the most recent ones having the designation of NLX. Right now, the designation ATX is the most prevalent. By buying a computer with a true ATX motherboard, you are assured that you will have the ability to upgrade by being able to re-use the personal computer case with a more recent replacement ATX board design. Motherboards have helped to keep the "personal" in personal computing since pluggable components allow the user to personalize the system depending on their applications and needs. For example: A prolific collector of digital camera images or video will want to add a SCSI hard disk drive to an open bay and use an empty socket on the motherboard for the SCSI controller card. A serious game enthusiast will want the fastest video card possible with as much memory on the card as possible.
Common Motherboard Items
A motherboard is a multi-layered printed circuit board. Copper circuit paths called traces that resemble a complicated roadmap carry signals and voltages across the motherboard. Layered fabrication techniques are used so that some layers of a board can carry data for the input/output, processor and memory buses while other layers can carry voltage and ground returns without circuit paths short-circuiting at intersections. The insulated layers are manufactured into one complete, complex "sandwich." Chips and sockets are soldered onto the motherboard. For example, you will typically find: - one or more microprocessors
- a basic input/output system chip (BIOS)
- memory slots
- a chip set that adds lots of features like I/O ports and controllers
- peripheral component interconnect (PCI) adapter card slots
- industry standard architecture (ISA) adapter slots
- accelerated graphics port (AGP) video card slots
- universal serial bus (USB) ports
- cooling fan(s) on heat sinks of processor and some video cards
Examples
The MSI 694D Pro AR supports dual Pentium central processing units (CPUs), has five PCI slots and a communications network riser (CNR) slot. The board supports 133 MHz bus speeds and ultra-direct memory access-100 (UDMA). There are four USB ports and onboard audio in the ATX form factor board. 
MSI 694D Pro AR Dual Flip Chip Socket 370 Motherboard |
The Abit KT-7A supports Advanced Micro Devices (AMD) processors and has the KT-133A chipset. The card slots on the Abit KT-7A, from bottom to top, shows below that ISA has one slot, PCI has six slots and AGP has one slot. A special fan cools the chipset. 
Abit KT-7A AMD Processor Motherboard |
A partial view of the TechRam S3ProM motherboard shows slots, from bottom to top, that ISA has one slot, PCI has two slots, audio modem riser (AMR) has one slot, and AGP has one slot. 
TechRam S3ProM Motherboard |
The BIOS chip is common to many motherboards. 
BIOS Chip |
Data Bus Width
Modern Pentium class motherboards have a data bus with 64 bits. That is the width of the data highway that goes in and out of the processor. The Pentium processors, however, do use 32-bit registers to handle 32-bit instructions. Bus speeds and widths have increased due to faster processors and the needs of multimedia applications. Typical bus names and widths (in bits) are: - Industry Standard Architecture (ISA) - 8 or 16 bits
- Extended Industry Standard Architecture (EISA) - 8 or16 bits
- Microchannel Architecture (MCA) - 16 or 32 bits
- VESA Local Bus (VLB) - 32 bits
- Peripheral Component Interconnect (PCI) - 32 or 64 bits
- Accelerated Graphics Port (AGP ) - 32 bits
How Have Motherboards Changed?
Speeds, temperatures, density, faster chipset designs and component count have driven the need for circuit cooling via miniature electric fans. These fans mount inside the actual computer case. Heat sinks act like an automobile radiator and provide additional surface area to help cool a component. Replaceable fan-heat sink assemblies are often used to help dissipate the considerable amount of heat on modern processor chips. The fan-heat sink assembly conducts heat away from the chip by convection, using a layer of thermal grease between the two mating metal surfaces. Fans often have a third wire used for monitoring the speed of the fan. Modern motherboard designs include provisions for monitoring: - fan speed in RPM for the personal computer case, processor and power supply fans
- temperatures of motherboard and processor
- personal computer case intrusion
PCI slots are replacing the older ISA slots, and both types of slots are being replaced by USB ports. USB ports can also be used to replace the usual keyboard, mouse and printer ports. Sound card function is also typically incorporated into modern motherboards. Multifunction chips are on the horizon that will do even more multiple tasks. The additional function on the motherboard saves the motherboard manufacturer costs because: - there are less warranty claims due to problems associated with all the many electrical contacts (fasteners) in the usual card slot
- there are lower power supply wattage requirements
- there are savings from elimination of a slot's socket and its space on the motherboard
The consumer can still upgrade function integrated on the motherboard (such as audio and game controls) so long as the motherboard manufacturer provides a means of disabling the function in order to prevent subsequent system resource conflicts. A motherboard still may have voltages present on it even if the computer is switched off due to recent advances in power management and power controls. Always make sure that the power cord is unplugged! Chipsets
Chipsets provide the support for the processor chip on the motherboard. The Intel 440BX is the dominant chipset in the non-Apple personal computers. The chipset is the heart of the computer since it controls and determines how fast and which type of processor, memory, and slots are used. Another chip on the motherboard is called the Super I/O controller. Its main function is to control the floppy disk drive, keyboard, mouse, serial and printer ports. Recent motherboard designs include additional chips to support USB, sound card, video adapter, computer host and network adapter. These chips save the cost of an adapter slot. Advice on Motherboards
When buying a motherboard, follow these tips: - Deal only with a reputable manufacturer.
- Ensure that it has the same form factor as your current case.
- Read the booklet that comes with your motherboard. It should fully cover the motherboard's settings and specifications.
- Check the power supply requirements for AMD processors. Some motherboards have unique requirements.
- Verify the form factor of your computer case matches the form factor of any motherboard you plan to buy.
- Avoid tweaking voltages and timings to get more speed out of a computer ("overclocking")."
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The, motherboard, has, been, an, integral, part, of, most, personal, computers, for, more, than, 20, years., Think, of, a, motherboard, as, a, scale, model, of, a, futuristic, city, with, many, modular, plug-in, buildings, each, using, power, from, a, common, electrical, system., Multi
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Computer viruses are mysterious and grab our attention. Every time a new virus hits, it makes the news if it spreads quickly. On the one hand, viruses show us how unknowingly vulnerable we are. A properly engineered virus can have an amazing effect on the world-wide Internet. On the other hand, they show how sophisticated and interconnected human beings have become. For example, the "Melissa" virus -- which became a worldwide phenomenon in March of 1999 -- was so powerful that it forced Microsoft and a number of other very large companies to completely turn off their e-mail systems until the virus could be contained. The "ILOVEYOU" virus in 2000 had a similarly devastating effect. That's pretty impressive when you consider how simple the Melissa and ILOVEYOU viruses are! In this edition of Stuff.dewsoftoverseas.com we will discuss viruses -- both "traditional" viruses and the newer e-mail viruses -- so that you can learn how they work and also understand how to protect yourself. Viruses in general are on the wane, but occasionally a person finds a new way to create one and that's when they make the news! When you listen to the news, you hear about many different forms of electronic infection. The most common are: Viruses - A virus is a small piece of software that piggy-backs on real programs. For example, a virus might attach itself to a program like a spreadsheet program. Each time the spreadsheet program runs, the virus runs too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc. Email viruses - An email virus moves around in email messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim's email address book. Worms - A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there as well. Trojan Horses - A trojan horse is simply a normal computer program. The program claims to do one thing (e.g. - it claims to be a game) but instead does damage when you run it (e.g. - it erases your hard disk). Trojan horses have no way to replicate automatically.
The infections in the news right now are worms, so let's take a look at worms and then go into the details on all of the different types of infection. Computer, viruses, are, mysterious, and, grab, our, attention., Every, time, a, new, virus, hits, it, makes, the, news, if, it, spreads, quickly., |
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