Overview/Questions
CS101 Lecture 02b:
Computer Terminology
– What are the main parts of a computer?
– How to talk about numbers…
– What does all the jargon in a computer ad
mean?
Some material copyright Jones and Bartlett
Some examples reproduced from Mark Allen Paulos’ book Innumeracy
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Hardware Basics
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Thinking Inside the Box
Hardware: the machinery of computing.
A computer’s internals are typically hidden
from the user. They consist of:
– Integrated circuit chips such as the central processing
unit (CPU), memory
memory circuits, and device controllers.
– Integrated devices for storage (e.g. hard disk),
communication (e.g. network adapter, Bluetooth).
– Greenboard and connecting wires.
The von Neumann computer architecture.
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Thinking Inside the Box
Thinking Outside the Box
A computer motherboard
The stuff that connects to the computer’s
box are called peripherals. These include:
– Input devices (e.g. keyboard, mouse)
– Output devices (e.g. video displays, printers)
– Storage devices (e.g. hard drive, USB key)
A CPU Chip
Some typical components in 1993.
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Computer Components
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Computer Components
What does all this jargon mean?
Consider the following ads*
– Intel 2.0GHz Core 2 Duo
– 1 GB RAM
– 120 GB HD
– DVD Burner/Combo Drive
– 13.3” display, 1280 by 800
What does all this jargon mean?
* University Computers, 1/20/2008
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Talking about Numbers
Scientific Notation
Many educated people have little grasp for
very big or very small numbers.
– A million is 1,000,000
– A billion is 1,000,000,000
– A trillion is 1,000,000,000,000
There’s nothing very tricky about it!
10N is 1 with N zeros after it:
103 is a thousand, or 1,000
106 is a million, or 1,000,000
109 is a billion, or 1,000,000,000
1012 is a trillion, or 1,000,000,000,000
Scientific Notation is clearer and easier to
work with, and we’ll often use it in CS101.
4 X 109 is 4 X 1,000,000,000 or 4,000,000,000
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Scientific Notation
Scientific Notation
There’s nothing very tricky about it!
10-N is 1 divided by 10N :
Why don’t newspapers and magazines
make appropriate use of scientific notation
in their stories?
10-3 is a thousandth, or 0.001
10-6 is a millionth, or 0.000001
10-9 is a billionth, or 0.000000001
10-12 is a trillionth, or 0.000000000001
3.4 X 10-7 is
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3.4 X 1/10000000 or 0.00000034
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The expression: 7.39842 X 1010
is more comprehensible than saying,
seventyseventy-three billion nine hundred and
eighty four milling two hundred thousand.
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Sizes in Perspective
Order of Magnitude
Sizes used in describing computer stuff:
An import concept about numbers is how to
compare numbers to see if one is bigger/smaller
than the other.
The order of magnitude compares the relative
size of some numbers.
Examples:
giga (109) is 1000 times bigger than mega (10
(106)
micro (10-6) is 1000 times smaller than milli (10-3)
We’ll discuss power of 2 numbers next time
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Computer Components
Units of Measurement
What does all this jargon mean?
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–
–
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Byte
A unit of storage which can hold a single (English)
character of text. (We’ll discuss other kinds of data later.)
Intel 2.0GHz Core 2 Duo
1 GB RAM
120 GB HD
DVD Burner/Combo Drive
13.3” display, 1280 by 800
Hertz
A measure of the speed of a cycle (repeated action).
The second hand of a clock ticks at 1 Hertz.
The G’s mean giga (billion) or 109.
What are the units of measurement?
Pixel
A unit of visible color/light on a digital screen.
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Computer Components
Computer Components
What does all this jargon mean?
What does all this jargon mean?
– Intel 2.0GHz Core 2 Duo:
The Hz mean Hertz, so 2.0 GHz is 2.0 X 109
operations per second -- the speed of the Central
Processing Unit.
– 1 GB RAM
The B means bytes, so 1 GB is 1 gigabyte or 109
bytes -- the amount of main memory or RAM.
– 120 GB HD
The B means bytes, so 120 GB is 120 X 109 bytes -the amount of storage space on the hard disk.
– DVD Burner/Combo Drive
Describes the read/write media drive: it can
read/write CD and DVD media.
– 13.3” display, 1280 by 800 native resolution
The size of the display is measured 2 ways:
ƒ in inches diagonally (top(top-left to bottombottom-right)
ƒ in the number of addressable pixels (called
resolution) 1280 wide by 800 high
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Miniaturization
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How Fast Do Electrons Go?
The internal parts of a computer (e.g. the
processor are extremely small. Why?
An electron can travel:
– A 1,000 foot long piece of wire in the time of
a microsecond (10-6 second)
– A foot long piece of wire in the time of a
nanosecond (10-9 second)
It has to do with the movement of
electrons through conductors.
The smaller, the faster!
– The length of a finely ground pepper grain in
the time of a picosecond (10-12 second)
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Summary
– The main parts of a computer are its
processor and memory, storage devices, and
input/output devices.
– Scientific notation provides a clear way to talk
about and compare very large/small numbers.
– Bytes, Hertz, and Pixels are units of
measurement for describing the capacities of
various components of a computer.
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