Topic:
• Processor
• RAM
• Motherboard
• HardDisk
• Cards
• Ports
• BIOS
• Peripherals
• Cabinet
• Troubleshooting
Processor
• Processor is the brain of your computer.
• Some key concepts
– Clock : In a computer, clock speed refers to the number of pulses
per second that sets the tempo for the processor.
– Cache
∗ A small but fast memory area.
∗ Levels of cache exists.
– Bus (FSB and BSB) : Collection of wires connecting different
devices.
– Pipeline : Implementation technique where multiple instructions
are ovelapped.
Processor contd...
• 32/64 bit processors
– The amount of data a processor can process in a clock cycle.
• Clock speed and overclocking
– BUS SPEED x MULTIPLIER = CPU SPEED (Clock)
• Which processor is faster?
– 100MHz x 10.0 = 1000 MHz
– 133MHz x 7.5 = 997.5 MHz
Some commercially available
processors
• Pentium I-IV
• Celeron
• Athlon
• Duron
• Cyrix C3
• Itanium (64 bit)
• Opteron (64 bit)
Processor contd...
• How do you pick a processor for your system?
– Performance & Cost
• How to measure performance?
– Clock speed is one measure of computer “power”, but it is not
always directly proportional to the performance level.
– The type of microprocessor, the bus architecture, and the nature
of the instruction set, all make a difference.
∗ examples : P4 3.06 GHz, P4 3.0B GHz, P4 3.0C GHz
– Check for bus speed and cache size as well.
RAM
• What is RAM?
– Random Access Memory.
– RAM is volatile.
• Broadly classified as
– Static RAM.
– Dynamic RAM.
RAM contd...
• Static RAM
– Fast, has lower access time.
– Typical access times 5-25 ns.
– Expensive.
– Cache memory is Static RAM.
• Dynamic RAM
– Slower, has higher access time than Static RAM.
– Typical access times 60-120 ns.
– Much cheaper than SRAM.
– Main Memory is Dynamic RAM.
RAM contd...
• Memory Bandwidth is proportional to System Bus speed.
• Dynamic RAM are further classified as
– EDORAM (Extended DataOut DRAM).
– SDRAM (Synchronous DRAM) : PC100, PC133.
– DDR SDRAM (Double Data Rate SDRAM)- Allows activation
of the output operation to occur on both rising and falling clock
edge and hence doubles the speed of operation.
– RDRAM (Rambus DRAM) - Developed by Rambus and Intel,
can support very high bus speeds.
RAM contd...
• Memory Slots/Sockets on Motherboard
– SIMM (Single In-Line Memory Module)
∗ Smaller in length and capacity than DIMM.
– DIMM (Dual In-Line Memory Module)
∗ Larger in length and capacity than SIMM.
– SIMM and DIMM are just packaging types only and do not affect the performance.
Motherboard
• The main circuit board which connects all the device on a microcomputer; Also called main board or system board.
Motherboard contd...
• Chipset
– The chipset controls the system and its capabilities. It is the hub
of all data transfer.
– Chipsets are integrated, and are not upgradable without buying
a whole new motherboard.
– Some of the items it dictates
∗ Memory controller
∗ Real-time clock
∗ Keyboard and mouse controller
∗ Secondary cache controller
∗ PCI bridge
∗ EIDE controller
Motherboard contd...
• Motherboards are designed for specific Processors. A single motherboard cannot be used with different types of Processors.
• The different system bus speeds supported by the Motherboard
should be of prime consideration.
Motherboard contd...
• Form Factors
– The form factor is the physical size and dimensions of the motherboard. The form factor determines the general layout, size,
and feature placement on a motherboard.
∗ Baby AT
∗ ATX
∗ Proprietary
Motherboard contd...
• Onboard devices - Video/Audio/LAN
– Lower cost.
– Lesser Flexibility.
• Upgradability
– Bus speeds supported.
– Number of expansion slots.
– Number and Types of IO ports available.
Hard Disk
• What is HardDisk?
– Stores data in magnetic
disk like medium
• Non-volatile mass storage device.
• Has very high access time
as compared to RAM (10-20
million ns).
• Very cheap as compared to
RAM and so large in capacity
Hard Disk contd...
• Interface standards
– IDE (Integrated Drive Electronics)
∗ The hard disk drive includes the drive controller circuitry and
hence known as IDE.
∗ It can support atmost 4 devices.
∗ 16 bit interface standard; 40 pin/80 pin connector.
∗ ATA-33/66
Hard Disk contd...
• Interface standards contd...
– SCSI (Small Computer System Interface)
∗ General pupose interface standard used for connecting many
types of devices to the PC.
∗ Supports 7 to 15 different devices like hard disk, scanner, CD
ROM etc.
∗ 32 bit interface standard and more expensive than IDE.
∗ Allows simultanous access for faster data transfer.
Hard Disk contd...
• Connecting Multiple IDE Harddisks/CD-Roms
– Primary/Secondary and Master/Slave settings
– Jumper settings
• Performance parameters
– Rotation speed.
– Average seek time.
Cards
Video Card
• What’s a Graphics Card?
– A modern graphics card is a circuit board with memory and a
dedicated processor.
– Converts digital information into the pixels to display it on the
monitor.
• Frame Buffers
– The card simply holds a frame of information that is sent to the
screen.
– Pixel updates are done by the microprocessor.
– Slow.
Video Card contd...
• Graphics accelerators with GPU
– Pixel updates are done by the GPU.
– GPU is optimised for graphics operations.
– Reduces load on the main processor.
Bus Interfaces PCI
• Peripheral Components Interconnect
Bus Interfaces AGP
• Accelerated Graphics Port
On board Graphics Accelerator
• On board graphics accelerators share system memory.
Video Card contd...
• Wide range of cards
– 3D Accelration.
– Video Memory.
• Modern day Graphics cards
are more powerful than Pentium processor!
• Expensive component of your
Computer.
Video Card contd...
• Choosing a Graphic card
– PCI or AGP.
– Integrated or Add-on card.
– Non-Accelrated or 3D accelrated.
– Cost.
Sound Card
• Converts digital data (bits) into analog sound wave and vice-versa.
• Has Digital Signal Processor, RAM, ADC and DAC.
• Has jacks for speaker, microphone, line in, line out and joysticks.
Sound Card contd...
• Choosing a soundcard
– Integrated or External add-on card.
– CPU Utilization.
– Sound reproduction capabilities (dolby, 5.1 channels etc.).
– Cost.
Network Interface Card
• Connects PC to LAN (Local
Area Network).
• Ethernet, Token Ring.
• Speeds
– 10Mbps
– 100Mbps
• Onboard or Add-on Card?
Ports
• Serial
– Serial port “serializes” data.
– Mouse, Modems etc use Serial port.
• Parallel
– Bits transmitted in parallel.
– Used primaraly for Printers.
• PS/2
– Used to interface keyboards and
pointing devices.
– Frees the serial port for other devices.
Ports contd...
• USB
– Data transfer rate 12Mbps/480Mbps.
– Multiple devices supported on the bus
(127).
– Hot pluggable, Plug-and-play.
– Provide power through the cable.
– Host based.
Ports contd...
• Firewire (IEEE 1394)
– Originally created by Apple and standardized in 1995.
– Fast transfer of data (up to 400 Mbps/800Mbps).
– Multiple devices supported on the bus (63).
– Hot pluggable, Plug-and-play.
– Provide power through the cable.
– Peer to peer.
– Supports synchronous devices.
BIOS
• What is it? - Basic Input Output System
• Why is it necessary?
– boot up
• Important Functions
– Check CMOS Set-up.
– POST - Power On Self Test.
– Display system setting.
– Initiate bootstrap sequence.
Configuring BIOS
• System Time/Date.
• Boot Sequence.
• Plug and Play.
• Drive Configuration.
• Security.
• Power Management.
Peripherals
Keyboard
• Switching action.
• No. of keys.
• Control, Functional, Special, Alpha-Numeric Keys.
• Connects to PC using PS/2 connector.
Mouse
• Different shapes and size.
• 2 and 3 buttons mouse.
• Scroll mouse.
• Connects to PC using PS/2 connector.
Monitor
• Cathode Ray Tube Monitor.
• Size - 15” to 21”.
• Resolution.
– CGA : 320 X 200 (4)
– EGA : 640 X 350 (16)
– VGA : 640 X 480 (256)
– SVGA : 1280 X 1024 (16.7 million)
• Display Quality - Refresh rate.
• Interlaced/Non-interlaced.
• Flat panel - LCD and Plasma.
CD ROM/Writable
• Speed - 12x, 24x, 48x, 52x etc.
• Sturdier, Unaffected by magnetic fields.
Printer
• Impact Printer - Dot matrix
– Selection : Speed, Unidirectional / Bidirectional.
– Adv. : Inexpensive, Multi-copy forms.
– Disadv. : Slow, Loud, Graphics of low Quality
• Non-impact Printer
– Inkjet
– Thermal
– Laser
– Adv. : Quiet, Can handle graphics, Varieties of fonts.
– Disadv. : Expensive.
Modem
• Speed - 56k, 33.6k, 28.8k
• Internal Modem
– Resides on the expansion board on the
slot of the motherboard.
– Does not require separate power
adapter.
– Cheaper than external modem.
– Has natural protection inside PC cabinet.
Modem contd...
• External Modem
– Resides on a self-contained box outside the PC.
– Requires external power adapter.
– Connected to PC’s serial port via the
cable.
– Easy to install and troubleshoot such
as resetting the modem.
– Expensive than internal modems.
Cabinet
• Form Factor
• AT Cases
• ATX Cases
AT Cases
• Older Motherboards (pre-pentium)
• Advantages
– Well Established standard make.
– Easy and cheap design.
• Disadvantages
– Inefficient cooling.
– CPU socket location.
– Not suitable for P-II (& higher).
ATX Cases
• Newer Motherboards (Pentium based m/c)
• Advantages
– Efficient cooling.
– Easy accessibility for upgades.
– I/O are fixed onboard.
Troubleshooting
• You are not the first one to face the trouble.
• Some simple solutions.
– Check connections.
– Ensure that cards are inserted properly.
– Clean the devices.
– Check if minimum things needed to boot are present - motherboard, processor, a full bank of memory, videocard and a drive
to boot.
Troubleshooting contd...
• The PC doesn’t start at all
– Count the number of beeps.
– No beeps - possible problem with BIOS or motherboard.
• The PC starts - partially
– No signal on the monitior.
– Video signal present with error mesage.
– OS starts.
– OS does not start - Hard-disk problem.
Troubleshooting contd...
• Video
– No video at all.
– Snow on the screen.
– The picture is horrible. Bad colors, dots, and streaks.
– Random, changing characters on the screen.
– The screen rolls upward or to the side.
Troubleshooting contd...
• Hard Drive
– Not bootable : A Hard Drive must be formatted and partitioned
before it can be used.
– Not detected by the BIOS - Check on a different m/c.
∗ It works fine.
∗ It does not work.
• Others
– System forgets time/settings
0 comments:
Post a Comment