What is S.M.A.R.T....???

                    Short for Self-Monitoring Analysis and Reporting Technology, S.M.A.R.T, orSMART, is a diagnostic method originally developed by IBM and introduced with theATA-3 specification that at that time referred to as Predictive Failure Analysis. This technology was initially developed for IBM mainframe drives to give advanced warning of drive failures. Based on this diagnostic, Compaq announced IntelliSafe, which was submitted to the ATA/IDE standards committees, and the resulting standard was named S.M.A.R.T.

S.M.A.R.T. analyzes many of the mechanical attributes; over time, some failures can be predicted by detecting if the hard drive is moving out of tolerance. While the S.M.A.R.T. technology can detect upcoming issues, not all hard drive failures are predictable. In the picture below is an example of a S.M.A.R.T error indicating that the status of the Pri Master or Primary hard drive is being detected as bad and that it should be replaced...

Some of the major hard drive manufacturers now including the S.M.A.R.T Technology in their hard drives are IBM, Western Digital, Maxtor, Quantum, Seagate and Fujitsu

What is IDE ,SATA, PATA...???

IDE

1. Short for Integrated Drive Electronics or IBM Disc Electronics, IDE is more commonly known as ATA or Parallel ATA (PATA) and is a standard interface for IBM compatible hard drives and CD or DVD drives. IDE is different from the Small Computer Systems Interface (SCSI) and Enhanced Small Device Interface (ESDI) because its controllers are on each drive, meaning the drive can connect directly to the motherboard or controller. IDE and its updated successor, Enhanced IDE (EIDE), are common drive interfaces found in IBM compatible computers. Below is a picture of the IDE connector on the back of a hard drive, a picture of what an IDE cable looks like, and the IDE channels it connects to on the motherboard.

Advantages of SATA over PATA

There are two types of hard drive connections that a computer could have: Parallel ATA (PATA) and Serial ATA (SATA). SATA is most commonly used in nearly all computers today, due to below mentioned advantages.

Advantages

Increased data transfer rate

The primary reason SATA is used over PATA is because of the increased data transfer speeds with that SATA. PATA is capable of data transfers speeds of 66/100/133 MBs/second, whereas SATA is capable of 150/300/600 MBs/second. The speed differences are due to the various flavors of PATA and SATA, with the fastest speeds being the latest version of each currently available. You'll notice that SATA's slowest speed is still faster than PATA's fastest speed. The improved speed of SATA allows for programs to load faster, as well as pictures and larger documents. For video game enthusiasts, faster data transfer speeds can mean better gaming experiences (i.e. smoother game-play).

Easy cable management and cable length

Another advantage of SATA over PATA is the length of the cable connecting the hard drive to the computer motherboard. The max length of a PATA cable is 18-inches, whereas a SATA cable can be up to 3.3 feet (1 meter) in length. This allows for more flexibility on where a hard drive can be mounted in a computer case.

Increased airflow

SATA cables are also smaller in size than a PATA cable, allowing for increased airflow inside the computer case and decreased heat build up. This can help improve the overall life of a computer.

Support for more drives

There are typically four to six SATA connections on a computer motherboard, allowing for multiple SATA hard drives to be hooked up. There are usually only two PATA connections on a computer motherboard that supports a total of four PATA hard drives.

Disadvantages

Drivers and support

There are only a few small disadvantages of SATA over PATA. One disadvantage is that SATA hard drives will sometimes require a specific driver to be loaded to a computer when installing an operating system, in order for the computer to utilize the SATA hard drive. This has more recently been rectified by allowing a SATA hard drive to act like a PATA hard drive, thus eliminating the need for the specific driver to be loaded. However, some SATA functionality will be lost in order to gain this mimic functionality.

Older operating systems such as Windows 95 and 98 that were released long before SATA was introduced do not support SATA drives.

One drive per cable

Another disadvantage with SATA is that the cable allows for only one SATA hard drive to be connected at a time. Whereas a PATA cable allows for hooking up two PATA hard drives per cable.

let a look on HD DVD and Blu - ray ...

 HD DVD

Short for High Definition Digital Versatile Disc, HD DVD is a high definition DVD standard jointly developed by NEC and Toshiba as a replacement for DVD. The first HD DVD player was released by Toshiba in Japan on March 31, 2006 and later an HD DVD player in a computer with its release of the Toshiba Qosmio 35 on May 16, 2006. HD DVD discs are capable of holding 15 GB per layer, which is almost three times more than the traditional DVD that is only able to hold 4.7GB.

HD DVD was backed by Intel, Microsoft, RCA, Sanyo, and Toshiba and had been in a format war with Blu-ray until February 19, 2008 when Toshiba officially announced it will no longer manufacturer HD DVD players or discs.

  BD

                  Short for Blu-ray Disc, BD or BD-ROM, is an optical disc jointly developed by thirteen consumer electronics and PC companies such as Dell, Hitachi, Hewlett Packard, LG, Mitsubishi, Panasonic, Sony, and TDK. The Blu-ray was first announced and introduced at the 2006 CES on January 4, 2006 and is capable of storing up to 25 GB on a single-layer disc and 50 GB on a dual-layer disc, each disc being the same size as a standard CD. The picture shows a blue laser in a Blu-ray disc player.

Today, Blu-ray is backed by Apple, Dell, Philips, Pioneer, Sony, Sun, TDK, and other companies mentioned above and beat out HD DVD in the high-definition disc format wars on February 19, 2008 after HD DVD called it quits.

What is S-Video ... ???

S-Video

Alternatively referred to as Y/C video, S-Video is short forSuper Video and is a round connector interface and cable that transmits video luminance (Y) and chrominance (C) signals separately. When received by the TV or other display device this generates a better picture when compared to composite video. The picture shows an example of an S-Video connector on the back of a video card.

What is Boot ???

Alternatively referred to as boot up, booting is the process of powering on a computer and getting into the operating system. During the boot process, the computer will perform a self-diagnostic, also known as a POST and load necessary drivers and programs that help the computer and devices communicate. As your computer is booting, you may see a screen similar to the example picture below.

In the above example, this screen is displaying the BIOS information, the type of computer, CPU, and memory for the computer and a prompt to enter BIOS setup.

If the computer cannot boot you may receive a boot failure, which is an error that indicates the computer is either not passing POST or a device in the computer such as the hard drive has failed.

What is RAM ???

Alternatively referred to as main memory, primary memory, or system memory,Random Access Memory (RAM) is a computer storage location that allows information to be stored and accessed quickly from random locations within DRAM on a memory module. Because information is accessed randomly instead of sequentially like it is on a CD or hard drive, the computer can access the data much faster. However, unlike ROM and the hard drive RAM is a volatile memory and requires power in order to keep the data accessible, if power is lost all data contained in memory lost.

As the computer boots up, parts of the operating system and drivers are loaded into memory, which allows the CPU to process the instructions much faster, hence taking less time before your machine is operational. After the operating system has loaded, each program you open such as the browser you're using to view this page is loaded into memory while it is running. If too many programs are open the computer will swap the data in the memory between the RAM and the hard disk drive.

Over the evolution of computers there has been different variations of RAM used in computer. Some of the more common examples are DIMM, RIMM, SIMM, SO-DIMM, and SOO-RIMM. Below is an example image of a 512MB DIMM computer memory module and what the typical desktop computer memory card will look like. This memory module would be installed intomemory slots on the motherboard.

MBR...???

          Short for Master Boot Record, MBR is also sometimes referred to as the master boot block, master partition boot sector, and sector 0. The MBR is the first sector of the computer hard drive that tells the computer how to load the operating system, how the hard drive is partitioned, and how to load the operating system.

In the above picture, is an example of what a partitioned hard drive may look like. In this case, the MBR is the first section of the hard drive the computer looks at after the BIOS hands control to the first bootable drive. Unlike the VBR, there is always only going to be a maximum of one MBR on a partitioned hard drive.

The MBR is also susceptible to boot sector viruses that can corrupt or remove the MBR, which can leave the hard drive unusable and prevent the computer from booting up. For example, the Stone Empire Monkey Virus is an example of an MBR virus.

EFI ???

Short for Extensible Firmware Interface, EFI is a new BIOS standard developed by Intel and introduced with the release of IA-64 that greatly improves the features available in the BIOS. Some of the major changes in EFI include getting rid of theboot loader, which allows the BIOS to select the operating system, EFI enables vendors to create drivers that cannot be reverse engineered, and has a small shellthat can be run at boot that allows a small and manageable working environmentwithout anything on the computer.

The EFI specification has been made into a general standard known as UEFI.

• The official Intel EFI specification page can be found athttp://www.intel.com/technology/efi/
• Computer motherboard help and support.

What is Bootstrap loader ???

    Alternatively referred to as bootstrapping, bootloader, or boot program, abootstrap loader is a program that resides in the computers EPROM, ROM, or othernon-volatile memory that automatically executed by the processor when turning on the computer. The bootstrap loader reads the hard drives boot sector to continue the process of loading the computers operating system. The term boostrap comes from the old phrase "Pull yourself up by your bootstraps."

The boot loader has been replaced in computers that have an Extensible Firmware Interface (EFI). The boot loader is now part of the EFI BIOS.

How does a computer work?...Detailed ...

How does a computer work?

This document has been created to give you a better understanding of how the personal computer works and what it does each time you press the power button.

Powering on the computer

When you first press the power button the computer sends a signal to the computer power supply, which converts the alternating current (AC) into a direct current (DC) to supply the computer and its components with the proper amount of voltage and electricity.

Once the computer and its components have received ample power and the power supply reports no errors it sends a signal (using transistors) to the motherboard and the computer processor (CPU). While this is happening, the processor will clear any leftover data in the memory registers and give the CPU program counter a F000 hexadecimal number. This number is the location of the first instruction and tells the CPU that it's ready to process the instructions contained in the basic input/output system (BIOS).

BIOS and the POST

When the computer first looks at the BIOS, it begins the power-on self-test (POST) sequence to make sure the components in the computer are present and functioning properly. If the computer does not pass any of these tests, it will encounter an irregular POST. An irregular POST is a beep code that is different from the standard one or two beeps. For example, an irregular POST could generate no beeps at all or a combination of different beeps to indicate the cause of the failure.

If the computer passes the initial POST, it will next look at the first 64-bytes of memory located in the complementary metal oxide semiconductor (CMOS) chip, which is kept alive by the CMOS battery even when the computer is turned off. This chip contains information such as the system time and date and information about all the hardware installed in your computer.

After loading the CMOS information, the POST will begin inspecting and comparing the system settings with what is installed in the computer. If no errors are found it will then load the basic device drivers and interrupt handlers for hardware such as the hard drive, keyboard, mouse, floppy drive. These basic drivers allow the CPU to communicate with these hardware devices and allow the computer to continue its boot process.

Next, the POST will check the real-time clock (RTC) or system timer and the computersystem bus to make sure both of these are properly working on the computer. Finally, you'll get a picture on your display after the POST has loaded the memory contained on the display adapter and has made it part of the overall system BIOS.

Next, the BIOS will check to see if it's currently performing a cold boot or warm boot(reboot) by looking at the memory address 0000:0472, if it sees 1234h the BIOS knows that this is a reboot and will skip the remainder of the POST steps.

If 1234h is not seen, the BIOS knows that this is a cold boot and will continue running additional POST steps. Next, it tests the computer memory (RAM) installed in the computer by writing to each chip. With many computers, you'll know it's performing this step if you see the computer counting the total installed memory as it's booting.

Finally, the POST will send signals to the computer floppy, optical, and hard drive to test these drives. If all drives pass the test, the POST is complete and instruct the computer to start the process of loading the operating system.

Booting the operating system

After the computer has passed the POST, the computer will start the boot process. This process is what loads the operating system and all of it's associated files. Because Microsoft Windows is the most commonly used operating system, this section will cover the process of loading Microsoft Windows.

The BIOS first hands control over to the bootstrap loader, which looks at the boot sector of the hard drive. If your boot sequence in CMOS setup is not setup to look at the hard drive first, it may look at the boot sector on any inserted floppy disk drive or optical disc first before doing this.

In this example, the Microsoft Windows XP NT Loader (NTLDR) is found on the boot sector and tells the computer where to find the remaining code on the hard drive. Next, Windows loads the ntdetect.com file, which displays the Windows splash screen and loads the Windows Registry. After loading the Registry, Windows begins to load dozens of low-level programs that make up the operating system into memory. Many of the initially loaded programs are what allow Windows to communicate with the essential hardware and other programs running on the computer.

After the Registry has loaded the initial basic hardware devices, it begins to load Plug and Play devices, PCI, and ISA devices. After loading all these devices, Windows then moves to loading full support of the hard drive, partitions, and any other disk drives and then moves to all other drivers that have been installed.

Finally, after successfully completing the above steps any additional required services are loaded and Windows starts.

What is the difference between BIOS and CMOS?

What is the difference between BIOS and CMOS?

The BIOS and CMOS are often times thought to be the same thing, but they are not. They are two different components of a computer, but they do work together to make the computer function properly.

The BIOS is a computer chip on the motherboard that resembles the picture to the right. This chip contains a special program that helps the computer processor interact and control the other components in the computer. These other components include disc drives, video cards, sound cards, network cards, floppy drives, USB ports, hard drives, and others. Without the BIOS, the processor would not know how to interact or interface with the computer components, and the computer would not be able to function.

 

The CMOS is also a computer chip on the motherboard, but more specifically, it is a RAM chip. This is a type of memory chip which stores information about the computer components, as well as settings for those components. However, normal RAM chips lose the information stored in them when power is no longer supplied to them. In order to retain the information in the CMOS chip, a CMOS battery on the motherboard supplies constant power to that CMOS chip. If the battery is removed from the motherboard or runs out of juice (e.g. a dead CMOS battery), the CMOS would lose the information stored in it. Any settings you made in the CMOS setup would be lost, and you would need to make those settings changes again after a new CMOS battery was put on the motherboard. For example, with a dead CMOS battery the time and date will reset back to the manufactured date if it has been off for a long period of time.

The BIOS program on the BIOS chip reads information from the CMOS chip when the computer is starting up, during the boot up process. You may notice on the initial start up screen, called the POST screen, an option is available to enter the BIOS or CMOS setup. When you enter this setup area, you are entering the CMOS setup, not the BIOS setup. The BIOS chip and program cannot be updated directly by a user. The only way to update the BIOS is using a BIOS flash program called a BIOS update, which updates the BIOS to a different version. These updates usually are provided by either the motherboard manufacturer or the computer manufacturer.

The CMOS setup lets you change the time and date and settings for how devices are loaded at start up, like hard drives, disc drives, and floppy drives. The CMOS setup lets you enable and disable various hardware devices, including USB ports, the onboard video card and sound card (if present), parallel and serial ports, and other devices.