Download Lecture 5 2008

LECTURE 5:
CPU and MEMORY
I. Four main types of electronic
components in computers:
1.
2.
3.
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transistors/resistors semi –
conductors that acts as an electronic
switch that can either conduct electricity
or prevent its flow
integrated circuit (a.k.a. “IC”) – a
chip that contains transistors/resistors
circuit board – the actual conductive
pathways that connect components
inside the CPU
all of these are mounted on a larger
circuit board called the motherboard
II. The CPU: Central Processing Unit
The CPU is the “brain” of the computer.
It:
receives input
 interprets instructions from programs
 processes data
 controls output
 directs other components of the system
to act

III. Parts of a CPU
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control unit – coordinates the flow
of data and instructions
ALU – (arithmetic logic unit)
performs calculations and
comparisons of data
registry – holds program
instructions, data, values, and
memory locations as the processor
executes a program
busses – carries information from
the CPU to a device
IV. Control Unit
the control unit contains a clock
that generates a uniform stream of
electrical pulses that synchronize the
operation of the CPU and other
components
 the faster this clock rate, the faster
the CPU can process information
 this clock speed is measured in
gigahertz (GHZ)

V. RAM: Random access Memory

Before programs are executed or before data is
processed they must enter into main memory
(a.k.a. primary storage or RAM)
Ram does the following:
 accepts and holds programs instructions and data
 acts as the CPU’s source of data and instructions as a
destination for operation results
 holds the final processed information until it can be sent to
the desired output or secondary storage device
 RAM is way faster to access than secondary storage
 Data is located in the main memory using addresses
 RAM is volatile (changeable) and requires constant change,
so save your work often to secondary storage
 ROM (read only memory) is different in that it is a
permanent instructions
Two Major Processors:
Intel
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8088
386
486
586 Pentium
Pentium 2
Pentium 3
Pentium 4
Core Duo and
Quad Duo
AMD
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Turon
Athlon
Opteran