The parts of a PC

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The parts of a PC
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Motherboard
RAM Slots
Expansion Slots (PCI)
Microprocessor Socket
AGP Slot
Input/Output ports
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Microprocessor Chip

• The BRAIN of the computer
• The Central Processing Unit (CPU)
• Speed is measured in Megahertz (MHz)

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Expansion Slots

• Memory, sound card, video card, internal modem,
  others.

PCI Card
5
Power Supply

• Converts service AC into DC
• 5V or less for the electronics
• 12V for the drives

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Memory

• A bit is the smallest amount of digital
  information (1 or 0)
• A Byte consists of 8 bits (0101 1011)
• Computers store information in Bytes

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Read Only Memory(ROM BIOS)

• Memory that contains the programs needed to start
  (boot) the computer and check its systems.
• BIOS stands for Basic Input/Output System.
• Also contains programs for moving information
  into and out of the computer.
• Programs in ROM are firmware and are
  permanently installed at the factory.

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Random Access Memory (RAM)

• The memory that holds application programs and
  user files.
• RAM is a poor term because it is really
  read-write memory.
• RAM is temporary, changeable storage.
• Early computers had only 640Kb of RAM
• Newer computer typically have more than 256Mb of
  RAM.

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RAM

• Three different areas in the computer where RAM
  is needed
• System
• Video/sound
• Cache
• RAM access time is measured in nanoseconds (nS)
  a billionth of a second.
• RAM works faster than ROM.

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Cashe Memory

• Part of RAM that helps speed up the computer by
  making frequently used instructions and data
  handy to the processor
• DRAM Dynamic RAM is constantly being refreshed
  depending on the needs of the computer
• SRAM Static RAM never needs to be refreshed.
  BIOS can be transferred from ROM to SRAM.
• Cashe is Handy Memory it exists on the
  processor, in DRAM, SRAM and other RAM. If the
  instruction or data cannot be found in RAM, the
  computer tries the hard drive (thrashing).

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Input/Output Devices

• An Input device SENDS information to the computer
• Keyboard, Mouse, Trackball, Scanner
• An output device DISPLAYS or TRANSMITS
  information from the computer
• Monitor, Printer, Speakers

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Monitor

• Displays the soft copy
• Resolution is the monitors ability to display
  images sharply and clearly.
• Resolution is measured in dot pitch (dpi)
• Touch screen allows you to press an option on the
  screen using your finger instead of a mouse.
• Screensavers for CRTs

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Video Cards

• Sometimes integrated with mother board.
• Available with different amounts of RAM
• Need more video RAM for graphics.
• You need two video cards if you use two monitors.

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The Keyboard

• Link to Shortcut Keys for Windows XP
• Link to more shortcuts.
• Function Keys (F1 through F12)
• Know what these keys do!

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Mouse

• Functions of the mouse

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Other I/O Devices

• Graphics Tablet
• Microphone
• Speakers
• Scanners
• Joysticks
• Camera
• Bar Code Reader
• Projector

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Ports

• Parallel Port
• Serial Port
• Small Comuter Systm Interface
• Universal Serial Bus
• Network port
• Musical Instrument Digitized Interface (MIDI)
• Infrared Ports

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Storage Systems

• Storage Systems are required to store software
  and user files.
• Remember that RAM is only temporary.
• You must SAVE your work to the hard drive before
  quitting.

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Storage Systems

• What and Why of storage systems
• Floppies
• Hard Disks
• CD drives
• Other

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Disk Drives

• Disks rotate at a constant speed (5400rpm)
• The read/write head moves across the disk surface.

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Hard Disk Format
Sector
Track

• Capacity may be 80Gb or more
• In 1986 20Mb was considered to be a large HD.

For more detailed info visit How Stuff Works
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Working with the HD

• The hard drive is the primary mass-storage
  device.
• Fast access to data on the disk.
• Can be separated into different volumes allowing
  each user to access only certain portions of the
  disk.
• Buy the largest capacity you can afford.

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CD Drives

• Data is stored by etching with a laser.

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CD

• 650 Mb
• The higher the speed of the disk, the faster the
  information can be transferred.
• CD-R drives are slower than CD-ROM drives.
• Try not to touch the bottom of the CD
• CD-R means write once
• CD-RW means write multiple times

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DVD

• 4.7 Gb to 17Gb (Movie is about 4.7Gb)
• Rapid access speeds
• DVD-ROM reads data only
• DVD-R Record once
• DVD-RW Record about 1000 times
• DVD-RAM Record about 100,000 times
• The user sees it as a hard drive.
• Available in cartridge form.
• Media not generally available at this time.

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Other Mass Storage Devices

• SuperDisk 120Mb but also reads 3.5 floppy
• Backup Tape 80Gb 7.2Gb per hour
• Zip Drive 250Mb
• Jaz Drive 2Gb (pretty much like Zip drive)
• Flash (Memory Card)
• Virtual Storage service (speed limited by
  Internet connection.)

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Floppy Disk Drive

• 3.5 removable disk (Cheap)
• 1.44 Mb (why bother ?)
• Newer computers will not have this kind of drive.

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Printers

• A printer for every need.

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Dot Matrix Printer

• Cheap to buy and maintain.
• Tractor Feed
• Resolution limited to 180 dots per inch
• Not for graphics.
• Forget color.
• OK for receipts, invoices, billing statements,
  and checks or any multi-part document (tear-apart
  carbon copies)

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Ink Jet and Bubble Jet Printer

• Quality almost as good as Laser Printer but costs
  less
• 64 nozzles with resolutions from 300 to 1200 dots
  per inch.
• Some units need special paper to ensure high
  resolution. (Photo Quality paper)
• Cheap paper can smear.
• Some technical differences between Ink Jet and
  Bubble Jet but the two machines perform much the
  same.

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Laser Printer

• Documents are written with a laser onto a
  photosensitive drum. Printer is sometimes
  combined with the office copier.
• Toner is picked up wherever the laser has written
  the document.
• 300 to 1200 dpi
• Cost per page is low.
• Maintenance cost is low.
• Color is possible but expensive

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Plotters

• Used for making line drawings on very large
  sheets of paper.
• Being replaced by very large laser printers.

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Photo Printers

• For printing photographs.
• Can print directly from a digital camera onto
  photo quality paper.

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Recycling Printer Supplies

• Paper should be recycled.
• Printer ink/toner cartridges are damaging to the
  environment and should be reused.
• Refill them yourself
• Send them to manufacturer for reuse.