2 Computer Hardware - Harith

7/27/2019 2 Computer Hardware - Harith

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Ak Abd Harith bin Pg Abdul Rahim HND in Communications and Computer Systems

Engineering

CCSE | Intake 29 (2013) |Group 3

Computer

Hardware Second Assignment For Semester 1

Computer Systems and Applications



PAGE 1

Different kinds of motherboards:

XT

AT – Advanced Technology

Baby-AT

ATX

Mini ATX

Micro ATX

Flex ATX Mini ITX

Nano ITX

Pico ITX

Mobile ITX

BTX

Micro BTX



PAGE 2

Fig. 1.1 An example of an ATX motherboard

Fig. 1.2 An example of an AT motherboard



PAGE 3

Difference between AT and ATX motherboard:

AT ATX

Older Newer (More commonly usednowadays)

13.8” × 12” (Wider in size) 12" x 9.6"

Not possible to customize portsin the back with backplates

Possible to customize the ports inthe back with backplates

Power switches connecteddirectly to the power supply

Power switch connected directly to the board

Number of pins on various connectors:

USB – 4 pins

IDE – 40 & 44 pins

SATA – 7 pins

ATX POWER CABLE – 24 pins, 20pins, 4 pins & 8 pins

PCI EXPRESS POWER CABLE – 6/8 pins

PARALLEL PORT – 25 pins

ETHERNET PORT – 8 pins

PC MOLEX CONNECTORS – 3 & 4 pin fan connector, 4 pins Floppy

power (mini-molex), 4 pin disk drive connector (Molex 8981)

PS/2 CONNECTOR – 6 pins

AT KEYBOARD CONNECTOR – 5 pins

VGA CONNECTOR – 15 pins

FIREWIRE CONNECTOR (IEEE 1394) – 4, 6 & 9 pins



PAGE 4

DC Voltages from the DC power supply:

3.3 volts

5 volts

12 volts

Electrical problems when operating the PC:

Overheating

Electrostatic charges

Hardware failures

ESD, EMI and RFI:

ESD - Electrostatic discharge is the release of static electricity when

two objects come into contact.

EMI – ElectroMagnetic Interference, a naturally occurring phenomena

when the electromagnetic field of one device disrupts, impedes or

degrades the electromagnetic field of another device by coming into

proximity with it.

In computer technology, computer devices are susceptible to EMI

because electromagnetic fields are a byproduct of passing electricity through a wire. Data lines that have not been properly shielded are

susceptible to data corruption by EMI.



PAGE 5

RFI – Radio Frequency Interference is when an electromagnetic

radiation which is emitted by electrical circuits carrying rapidly

changing signals, as a by-product of their normal operation, and which

causes unwanted signals (interference or noise) to be induced in othercircuits.

The most important means of reducing RFI are: use of bypass or

"decoupling" capacitors on each active device (connected across the

power supply, as close to the device as possible), risetime control of

high speed signals using series resistors and VCC filtering. Shielding is

usually a last resort after other techniques have failed because of theadded expense of RF gaskets and the like.

PC storages:

Hard disk driveCompact disk

Digital Versatile Disk

USB drive

Blu-ray disk

Floppy disk

Memory disk

Fig. 2.1 An example of a hard disk drive



PAGE 6

RAM and pin numbers:RAM Slot Pins

DRAM (DynamicRAM)

SIMM 72

EDO DRAM (Extendeddata-out dynamic

RAM)

SIMM 72

RDRAM (RambusDRAM)

RIMM 184

SDRAM (SynchronousDRAM)

SODIMM

DIMM

144

168

DDR (Double datarate)

MicroDIMM

SODIMM

DIMM

172

200

184

DDR2

MicroDIMM

SODIMM

DIMM

214

200

240

DDR3

MicroDIMM

SODIMM

DIMM

214

204

240

GDDR3 DIMM 240

VRAM (VideoRAM) SIMM 72

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2 Computer Hardware - Harith