Summary Information Technology IEB Grade 12/11 Theory

IT THEORY NOTES




Table of Contents
GRADE 11 HARDWARE + SOFTWARE:....................................................................................................1
GR 12 HARDWARE + SOFTWARE..........................................................................................................11
ADDITIONAL HARDWARE + SOFTWARE...............................................................................................19
NETWORKS + E-COMMUNICATIONS....................................................................................................20
INTERNET.............................................................................................................................................22
SOCIAL IMPLICATIONS.........................................................................................................................27
DATABASE MANAGEMENT..................................................................................................................31

,GRADE 11 HARDWARE + SOFTWARE:

Motherboard:


 is a large circuit board which connects the most important components of
the computer such as the CPU, memory and connectors for peripherals.
o co-ordinates the interactions between the components as efficiently
as possible.


Chipset:


 These are sets of chips used on MB to connect components.


 Controller hardware:
o Controller is circuitry responsible for a specific piece of hardware in
the computer system.


 DMA: Direct memory access is a controller for the memory.


 Chipsets contain: logic circuits to support processor of the mother board.


Northbridge (Memory Controller Hub):


o Connects CPU, RAM, Graphics card and South bridge.


South-bridge (Platform Controller Hub):


o Is in charge of controlling I/O devices and on-board devices e.g. USB
ports and BIOS and CMOS.


***North Bridge and South bridge belong to one specific chip set.




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,The PCI bus (peripheral component interconnect bus)


 connected the North Bridge and the South bridge.
 This caused a bottleneck due to the PCI bus’s bandwidth and
that’s why they made an AGP (Accelerated graphics port) to not
suppress the graphics card.


FSB (front side bus)


 parallel bus that connected all components of the motherboard: (connects
the CPU and the North bridge)
 REPLACED BY point-to-point serial connections.
 Was Cheap and easy.
 CONTAINS:


o ADDRESS BUS- transfers the physical address of computer from the
CPU to RAM


o DATA BUS- transfers data from the CPU to RAM


o CONTROL BUS- transfers actual commands from the CPU to RAM


HyperTransport bus


 AMDs improvement on the FSB by providing separate links for the CPU
input and output operations allowing the CPU to transmit and receive I/O
data at the same time in parallel.


PCH (South bridge) - orientated platform:


 They changed to a PCH-orientated platform to prevent the bottle neck
between the processor and the mother board, as the speed of the CPU
was increasing the FSB was not therefore there would be a problem,
between the CPU and MB.


 Northbridge was eliminated
 Now there is an IMC = integrated memory controller


Processor trends:



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,  more functions onto a single chip.


Speeds:


 System Clock provides a pulse, the clock signal regulated the flow of logic
signals so that the system can run at optimum speed. The speed is
determined by the rate at which the crystal in the chip vibrates when
current passes through.


o CPU = 8x speed of the FSB


o Memory = same speed as CPU


o Peripheral bus = fraction of the speed of the front side bus


 Overclocking = practice of making components operate beyond their
stock component levels.
o When you speed up your CPU to a processing speed which it was
not intended to be run at by default.
 Can be done through increasing voltage
 INCREASING SYSTEM CLOCK to increase the frequency of
component.
 This can cause over heating or even premature failure.


Clock multiplication = INCREASING THE CLOCK MULTIPLICATION FACTOR
 Clock multiplication factor= Speed ratio between the CPU and the FSB


The processor (CPU)
 control units and arithmetic logic units.
 It’s a chip on the motherboard responsible for processing and executing
instructions.
o FETCH - fetch instruction
o DECODE - understand the instructions
o EXECUTE - perform the action (instructions)
o STORE - send result back to main memory of device


External buses = a type of data bus that enables external devices and
components to connect to a computer such as a keyboard.


USB ports = Universal Serial Bus is a standard of connecting most devices to a
computer.
PCI = fixed width of 32 bits and can only handle 5 devices.


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