NEW MOTHERBOARD

A motherboard is the central printed circuit board (PCB) in some complex electronic systems, such as modern personal computers. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple computers, the logic board. It is also sometimes casually shortened to mobo.

History

Prior to the advent of the microprocessor, a computer was usually built in a card-cage case or mainframe with components connected by a backplane consisting of a set of slots themselves connected with wires; in very old designs the wires were discrete connections between card connector pins, but printed-circuit boards soon became the standard practice. The central processing unit, memory and peripherals were housed on individual printed circuit boards which plugged into the backplane.

During the late 1980s and 1990s, it became economical to move an increasing number of peripheral functions onto the motherboard (see below). In the late 1980s, motherboards began to include single ICs (called Super I/O chips) capable of supporting a set of low-speed peripherals: keyboard, mouse, floppy disk drive, serial ports, and parallel ports. As of the late 1990s, many personal computer motherboards supported a full range of audio, video, storage, and networking functions without the need for any expansion cards at all; higher-end systems for 3D gaming and computer graphics typically retained only the graphics card as a separate component.

Compact Disk Drive

• The CDD installs in one of the external 5-1/4 inch drive bays in the front of the PC case. It is secured by machine screws. Some manufacturers offer special rail-like systems that mount on the CDD. These allow the drive to be removed from the PC without having to remove any screws.
  
  
• Data is stored optically on the surface of the disk. A laser attached to an arm that moves back and forth across near the disk surface and sends light toward the disk surface which is coated with of a thin layer of aluminum.
  
  
• Smooth areas called a lands reflect the light back to a photo diode located near the laser. The reflected light is read as a 1. Areas called pits are where the aluminum has been removed. When the laser light hits these, it is scattered and very little is picked up by the photo diode. The absence of light is read as a 0.
  
  
• CDD have become the predominant removable storage media for PCs and can store 700 Mbytes of data.
  
  
• A 4-pin cable from the power supply plugs into the CDD and provides power to it.
  
  
• Data to and from the motherboard is carried on a 40-pin IDE (Integrated Drive Electronics) cable.
  
  
• There are two types of Compact Disk drives available for PCs.
  
  
  1. CD-ROM (read only memory) is the older type. As the title implies it can only read CDs. It can read any standard CD and most CD-R type disks. It may be able to read some types of CD-RW disks too. A 24x CD-ROM unit costs about $30.
     
     
  2. CD-RW (ReWritable)units can read and write CD-R and CD-RW type disks. It can also read standard CD type disks.
     A 24x10x40 CD-RW unit costs about $115. The 24x10x40 means the unit can write at 24x, re-write at 10x and read at 40x, where x is 150Kbytes/sec.

Input

Main article: Input

• Text input devices
  • Keyboard - a device to input text and characters by depressing buttons (referred to as keys), similar to a typewriter. The most common English-language key layout is the QWERTY layout.
• Pointing devices
  • Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
  • Optical Mouse - a newer technology that uses lasers, or more commonly LEDs to track the surface under the mouse to determine motion of the mouse, to be translated into mouse movements on the screen.
  • Trackball - a pointing device consisting of an exposed protruding ball housed in a socket that detects rotation about two axes.

• Gaming devices
  • Joystick - a general control device that consists of a handheld stick that pivots around one end, to detect angles in two or three dimensions.
  • Gamepad - a general handheld game controller that relies on the digits (especially thumbs) to provide input.
  • Game controller - a specific type of controller specialized for certain gaming purposes.
• Image, Video input devices
  • Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
  • Webcam - a low resolution video camera used to provide visual input that can be easily transferred over the internet.
• Audio input devices
  • Microphone - an acoustic sensor that provides input by converting sound into electrical signals.
  • Mic - converting an audio signal into electrical signal.

Internal storage

Hardware that keeps data inside the computer for later use and remains persistent even when the computer has no power.

• Hard disk - for medium-term storage of data.
• Solid-state drive - a device similar to hard disk, but containing no moving parts and stores data in a digital format.
• RAID array controller - a device to manage several internal or external hard disks and optionally some peripherals in order to achieve performance or reliability improvement in what is called a RAID array.

Removable media devices

Main article: Computer storage

• CD (compact disc) - the most common type of removable media, suitable for music and data.
  • CD-ROM Drive - a device used for reading data from a CD.
  • CD Writer - a device used for both reading and writing data to and from a CD.
• DVD (digital versatile disc) - a popular type of removable media that is the same dimensions as a CD but stores up to 12 times as much information. It is the most common way of transferring digital video, and is popular for data storage.
  • DVD-ROM Drive - a device used for reading data from a DVD.
  • DVD Writer - a device used for both reading and writing data to and from a DVD.
  • DVD-RAM Drive - a device used for rapid writing and reading of data from a special type of DVD.
• Blu-ray Disc - a high-density optical disc format for data and high-definition video. Can store 70 times as much information as a CD.
  • BD-ROM Drive - a device used for reading data from a Blu-ray disc.
  • BD Writer - a device used for both reading and writing data to and from a Blu-ray disc.
• HD DVD - a discontinued competitor to the Blu-ray format.
• Floppy disk - an outdated storage device consisting of a thin disk of a flexible magnetic storage medium. Used today mainly for loading RAID drivers.
• Zip drive - an outdated medium-capacity removable disk storage system, first introduced by Iomega in 1994.
• USB flash drive - a flash memory data storage device integrated with a USB interface, typically small, lightweight, removable, and rewritable. Capacities vary, from hundreds of megabytes (in the same ballpark as CDs) to tens of gigabytes (surpassing, at great expense, Blu-ray discs).
• Tape drive - a device that reads and writes data on a magnetic tape, used for long term storage and backups.

Monitor

CRT Monitors

• Up until recently, CRTs (Cathode RayTubes) were the only type of displays for use with desktop PCs. They are relatively big (14" to 16" deep) and heavy (over 15 lbs).
  
  
• They are available in screen sizes from 14" to 21". A 17" display means that it is 17" measured diagonally from one corner of the tube to the other. The actual viewing area is smaller than 17" (about 16") since the electron gun can't sweep completely to the tube edge.
  
  
• CRTs send a stream of electrons at the screen, which is charged to about 25,000 volts. As they strike it they cause phosphor on the backside of the screen to glow creating light which you see. The electron stream is sweep back and forth and up and down at about 60 sweeps per second and turned off and on at the right time to make text and graphics images appear.
  
  
• They are powered by standard 120Vac wall power.
  
  
• Data is transferred to the display on a cable with a 15-pin D-shell connector that plugs into a connector on the video card which in turn plugs into one of the PC's expansion slots.
  
  
• A 17" monitor with 1280 x 1024 resolution and .27mm dot pitch sells for around $150.

LCD Monitors

• Liquid Crystal Display (LCD) technology has been used in laptops for some time. It has recently been made commercially available as monitors for desktop PCs.
  
  
• LCDs have no electron gun and are therefore not very deep like CRTs. The text and images you see are created by a back light behind the panel, that shines through pixels (picture elements). Each pixel is made up of three chambers red, green and blue. The chambers in each pixel must be opened enough and in the proper proportion to produce the correct brightness and color.
  
  
• For an LCD to provide a screen resolution 1024 x 768 pixels (SVGA), it must have 786,432 (1024 x 768) pixels. In TFT (Thin Film Transistor) type LCDs, each pixel is controlled by a tiny transistor that opens and closes the chambers in each pixel.
  
  
• Desk top LCD displays are powered by standard 120Vac wall power.
  
  
• Data is transferred to the display on a cable with a 15-pin connector that plugs into a mating connector on the video card seated in an expansion slot in the PC.
  
  
• A 17" LCD monitor with 1280 x 1024 resolution and .27mm dot pitch sells for around $500.

Personal computer hardware

A personal computer is made up of multiple physical components of computer hardware, upon which can be installed an operating system and a multitude of software to perform the operator's desired functions.

Though a PC comes in many different form factors, a typical personal computer consists of a case or chassis in a tower shape (desktop) and the following parts: You can find out more at http://www.hardware.com/

[edit] Motherboard

The motherboard is the "brain"^{[citation needed]} of the computer. Components directly attached to the motherboard include:

• The central processing unit (CPU) performs most of the calculations which enable a computer to function, and is sometimes referred to as the "brain" of the computer. It is usually cooled by a heat sink and fan.
• The chipset mediates communication between the CPU and the other components of the system, including main memory.
• RAM Stores all running processes (applications) and the current running OS. RAM Stands for Random Access Memory
• The BIOS includes boot firmware and power management. The Basic Input Output System tasks are handled by operating system drivers.
• Internal Buses connect the CPU to various internal components and to expansion cards for graphics and sound.
  • Current
    • The northbridge memory controller, for RAM and PCI Express
      • PCI Express, for graphics cards
    • PCI, for other expansion cards
    • SATA, for disk drives
  • Obsolete
    • ATA (superseded by SATA)
    • AGP (superseded by PCI Express)
    • VLB VESA Local Bus (superseded by AGP)
    • ISA (expansion card slot format obsolete in PCs, but still used in industrial computers)
• External Bus Controllers support ports for external peripherals. These ports may be controlled directly by the southbridge I/O controller or based on expansion cards attached to the motherboard through the PCI bus.
  • USB
  • FireWire
  • eSATA

Audio

• Speakers and headphones are the primary audio output devices for a PC.
  
  
• Some monitors have speakers built into their sides. Other speakers are free standing.
  
  
• Passive speakers plug into and are powered directly from the output signal provided by the 'speaker out' port on the sound card.
  
  
• Active speakers amplify the sound signal from the sound card using battery or rectified AC house power.
  

Digital Video Disk drive

1. DVD also known as the Digital Versatile Disk drive, installs in one of the external 5 1/4 inch drive bays in the PC. It is secured by machine screws. Some manufacturers offer special rail-like systems that mount on the DVD. These allow the drive to be removed from the PC without having to remove screws.
   
   
2. It is designed to optically access data stored on a DVD. A laser moves back and forth near the disk surface and accesses data at a very fast rate.
   
   
3. A 4-pin cable from the power supply plugs into the CDD and provides power to it.
   
   
4. Data between the DVD drive and the motherboard is carried on a 40-pin IDE (Integrated Drive Electronics) cable.
   
   
5. There are two types of DVD drives that typically go into PCs.
   
   
   • DVD-ROM (Read Only Memory) can read DVDs and CDs and costs about $75.
     
     
   • DVD-RAM (Random Access Memory) units can read and write DVDs. They can also read CDs and cost about $500.
   
   
   
6. A standard DVD stores up to 4.7 Gbytes on one side of the disk. Digitally formatted movies can be stored on a standard DVD in MPEG-2 format.
   

Motherboard

The motherboard is the main circuit board in a PC. It contains all the circuits and components that run the PC.

Major Components found on the motherboard are:

• CPU - the Central Processing Unit is often an Intel Pentium or Celeron processor. It is the heart of every PC. All scheduling, computation and control occurs here.
  
  
• BIOS - Basic Input Output System is a non-volatile memory that contains configuration information about the PC. It contains all the code required for the CPU to communicate with the keyboard, mouse video display, disk drives and communications devices.
  
  When a PC is powered on it uses the BIOS 'boot code' to set up many required functions that bring the PC to a point where it is ready to work.
  
  
• RTC - the Real Time Clock chip keeps date, day and time in a 24 hour format just like your watch. The PC uses this clock to 'time stamp' files as they are created and modified. When you print a file it time stamps the pages as they are printed.
  
  
• Chip Set - these are large chip(s) that integrate many functions that used to be found in separate smaller chips on the motherboard. They save space and cost.
  
  The functions performed by these chip sets often broken into two devices with one providing an interface from the CPU to the memory and the other providing controllers for IDE, ISA, PCI and USB devices (see below).
  
  

Primary Connectors found on the motherboard are:

• Power - A 20 pin connector accepts a plug from the power supply. This plug carry DC power to all the circuits on the motherboard.
  
  
• Keyboard - A Mini-din 6-pin (round) connector found at the back of the motherboard is where the keyboard plugs in.
  
  
• Mouse - A Mini-din 6-pin connector found next to the keyboard connector is where the where the mouse plugs in.
  
  
• Display - This connector is not integrated into the motherboard but is included in this list since its function is absolutely necessary. It is a 15-pin, D-shell type connector found on a video card that plugs into the AGP connector of the motherboard (see below).
  
  
• IDE - stands for Integrated Drive Electronics. These are 40 pin connectors that provide a place to connect the ribbon cables from the drives (hard and CD/DVD). All data between the motherboard and the drives is carried in these cables. They are not accessible unless the PC cover is removed.
  
  
• FDD connector - it is similar in function to the IDE connector. It is a 34 pin ribbon connector that carries data between the motherboard and any floppy drive installed in the PC. Not accessible with PC cover on.
  
  
• DRAM - Dynamic Random Access Memory connectors for SIMM and DIMM type memory modules. Not accessible with chassis cover on.
  
  
• Serial Connectors
  
  
  • Standard Serial Connector - This connector has been around in PCs since they first appeared. It was originally located on ISA expansion type cards (see below). Today it is an integral part of newer motherboards. It is a 9- pin, D-shell connector that allows you to connect external devices with serial ports to your PC. The maximum data rate is 115 KB/s.
    
    
  • USB - Universal Serial Bus This is a relatively new serial bus. Originally specified as low speed, 1.2 Mb/s, it was enhanced to full speed, 12Mb/s. The latest version 2.0 is specified as high speed, 400 MB/s.
    
    Someday USB will completely replace the standard serial connector that has been the workhorse serial port in earlier PCs. USB is now a standard connector on all new motherboards.
    
    Unlike serial and parallel ports, the USB port is designed to power devices connected to it. The devices must be low power devices and must be able to reduce their current draw to less than 0.5uAmps when commanded to do so by the PC.
    
    
• Parallel Connectors
  
  
  • Centronix or Standard Parallel - This connector has been around in PCs since they first appeared. It has 37-pins and is now integrated on new motherboards. It is usually used to connect your printer to the PC and moves data at about 1MB/s.
    
    
  • SCSI - Small Computer System Interface moves data at a maximum of up to 80Mb/s. It not integrated into most PC motherboards. It can be added to a PC as an Expansion card (see below). Some printers and hard disk drives use SCSI interfaces.
    
    
• Expansion Card Connectors - The CPU connects to expansion card connectors through one of the chip set ICs mentioned above. They are located on the motherboard near the rear of the PC. These connectors allow special function cards to plug into and work with the PC.
  
  Before motherboards integrated the serial and centronix connectors they were found on expansion boards that plugged into ISA slots.
  
  Most PCs have the following expansion connector types:
  
  
  • ISA - Industry Standard Architecture connectors have been around since 1980 and first appeared in the IBM XT PC. This type of slot still appears on some newer motherboards so that older expansion boards can still be used. However, many motherboards no longer have ISA connectors on them.
    
    
  • PCI - Peripheral Component Interconnect is a newer and faster interface that accepts all expansion cards that have a PCI interface.
    
    
  • AGP - Accelerated Graphics Port is a connector that is designed to work with video cards. Your video display plugs into and is controlled by one of these video cards. Many modern video cards offer enhanced 3D-graphics and fast, full motion video.

Hardware

All the elements that go together to make up a PC fall into one of two categories, hardware or software. This section is about hardware, the stuff upon which software runs.

One of the definitions of 'hardware' according to Webster's dictionary is 'major items of equipment or their components used for a particular purpose'.

Everything you can see and touch in your PC is hardware. Complete PCs can be purchased for about $300 today, and the prices keep falling! All the items listed below that make up a PC can be purchased individually at computer or web supply stores.

This following list represents a basic set of hardware found in most PCs.
For more information on these components just click one.