This document discusses the basics of computing systems. It explains that a computer system requires data input which is processed into information. Data is represented using binary code as strings of 1s and 0s. Electricity and signals transmit this data, which can be either analog signals varying continuously in amplitude or digital signals taking on discrete binary values. The hardware components of a computer that process this data include the central processing unit with its registers, arithmetic logic unit, and control unit. Software provides the instructions to control the hardware and comes in application and system types, with the operating system managing interactions between software and hardware.

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Essentials of Computing

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OVERVIEW
• System
• Hardware and Software
• The Operating System

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System
• A computer needs data, which is simply raw
facts made up of words, numbers, etc.
• Data is input into the system, processed, and
transformed, by you, into information.

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System
• The raw facts in the definition of data come in a
specific form. This form is known as binary
code.
– Bi comes from the Latin word for two.
– In binary code, the data can be presented in
two options: a 1 or a 0.
View this link:
The Binary Code

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The Binary Code
FIGURE 3-2 Bits
can either be a 1 or
a 0. Eight bits make
up a byte or a
standard character.
The word CELIA is
made up of the
depicted bytes.

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System
• Electricity is actually defined as “the class of
physical phenomena arising from the existence
and interactions of electronic charge.”
– Therefore electricity is a phenomenon and voltage
measures its potential.
• If you vary these two in a consistent manner,
then you have a signal.
– A signal can travel down a wire or even through the
air. Signals come in two general categories: analog
and digital.
– Analog signals travel as a wave that has many points
or states.

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Analog and digital signals
• Analog and digital signals are used to transmit
information, usually through electric signals. In both
these technologies, the information, such as any
audio or video, is transformed into electric signals.
• The difference between analog and digital
technologies is that in analog technology,
information is translated into electric pulses of
varying amplitude. In digital technology, translation
of information is into binary format (zero or one)
where each bit is representative of two distinct
amplitudes.

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Analog and digital signals
Analog Digital
Signal Analog signal is a continuous signal
which represents physical
measurements.
Digital signals are discrete
time signals generated by
digital modulation.
Example Human voice in air, analog electronic
devices.
Computers, CDs, DVDs,
and other digital
electronic devices.
Data
transmissions
Subjected to deterioration by noise
during transmission and write/read
cycle.
Can be noise-immune
without deterioration
during transmission and
write/read cycle.

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Analog and digital signals
Analog Digital
Uses Can be used in analog devices only.
Best suited for audio and video
transmission.
Best suited for Computing
and digital electronics.
Applications Thermometer PCs, PDAs

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Hardware
• Hardware is something physical you can touch
and feel such as your computer screen.
– If you take off a cover of a computer, you
would see a green board with circuitry and
extensions.
– This is known as a printed circuit board (PCB)
or a motherboard.
– This is the foundation of the computer where
all of the connections take place.
• On this foundation sits the central processing
unit (CPU).

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Hardware
• The CPU is divided into four main parts:
– Register. Temporarily stores the pieces of
information being processed
– Arithmetic Logic Unit (ALU). Carries out
math and logic functions
– Control Unit. Coordinates the work of the
register and ALU
– Data Storage. Stores the results

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Hardware
• When computing devices operate, they follow
these four basic steps:
– Get instructions
– Decode instructions
– Execute instructions
– Store results

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Hardware
• When computing devices operate, they follow
these four basic steps:
– Get instructions
– Decode instructions
– Execute instructions
– Store results

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Smart phones and tablets
• A smart phone is a mobile phone that can
access the Internet and is increasingly
incorporating more PC-like features.
• Tablet PCs are flat computing devices that use
touch screens.

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Software
• Software is the detailed instructions that control the
operation of a computer system.
– “A software program is a series of statements or
instructions to the computer. The process of
writing or coding programs is termed
programming, and the individuals who specialize
in this task are called programmers”
• Software comes in two basic categories:
– Application software
– System software

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Operating systems and more
• Between the application software and the
hardware sits the system software, one major
part of which is the operating system (OS).
– By definition, the OS is “the system software that
manages and controls the activities of the computer”.
– Further, it serves as the “middle person” between the
application software and the hardware components.
• OS manages the computer hardware and
software while making sure that all tasks are
executed correctly.

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Operating systems and more

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Essentials of Computing