THE COMPUTER
The computer is a machine that accepts data as input, processes the data according to a set
of programmable rules, and produces the result as output.
Broken down into its two most fundamental components, a computer consists of the
physical machinery itself, known as the hardware, and the programs telling the computer
what to do, known as the software.
Computer hardware is simply a large amount of switches with the software controlling
how the switches should be set. The switches use values of 0 and 1 to represent whether
they are open or closed, and through this, a single unit of information can be stored in one
switch. This unit of information is known as a bit, which stands for ‘‘binary digit.’’ Typically
arranged into groups of eight, these eight bits make up one byte, which can hold 256 combinations,
or a number from 0 to 255.
These combinations of switches, however, are not limited only to representing numbers.
Based on the programmer’s preference, a particular combination of bits can represent a
specific number, letter, or even color for a graphics program.
Switches found inside a modern computer are not mechanical switches but electrical
ones that comprise a portion of a larger electrical circuit. The flow of electricity through
these switches is used to indicate the state of a switch and may, in turn, open or close other
switches. When enough switches are present, very complex calculations can be computed.
Within a modest modern computer, there are several million switches.
What is even more important than the sheer number of switches in a computer is the
speed at which these switches can be used. In a single second, one switch could turn on and
off more than a billion times, meaning that even complex tasks can be accomplished as fast
as the user can input the commands. This is possible because at the heart of these complex
commands are simple addition, subtraction, multiplication, and division commands utilizing
the switches as counters.
Beyond these switches, there are many other components that help to make up the entire
system. Broken down into its traditional components, the following are the hardware categories
you would find in a computer:
• Input Devices. Receive the information and instructions from the user and transfer
them into the computer.
• Memory. The array of switches that maintain an open or closed position until told to
change. This enables the computer to remember programs and information.
• Central Processing Unit. Where a majority of the calculations and processing of information
are completed utilizing a large array of switches.
• Output Devices. Display the results of programming after functions are performed.
• Storage. Maintains large amounts of information over a long duration of time.
Although this is the traditional breakdown of the components in a computer, these are
very ‘‘soft’’ boundaries, as can be seen with a floppy disk. In one instance, it can be seen
as an input device, delivering instructions to the computer. But in an entirely different instance,
it could be seen as an output device when data or programs are being written to it.
By the same token, there are also many devices that have fixed functions, such as the
keyboard and mouse being input devices.
The most basic form of software is known as the OS (operating system) and lies underneath
the most common software—those that are purchased or downloaded as special
applications. These applications are programmed to perform a specific task, such as word
processing or going onto the Internet. However, without the OS, these programs cannot run
because it is the OS that actually runs the computer.
However, beneath the OS resides the BIOS (basic input /output system), which instructs
the different components of the computer on how to communicate with each other. The
BIOS is typically embedded within the computer and is loaded immediately after the computer
is started.
COMPUTER-AIDED DESIGN
Emory W. Zimmers, Jr. and Technical Staff
Enterprise Systems Center
Lehigh University
Bethlehem, Pennsylvania
Mechanical Engineers’ Handbook: Materials and Mechanical Design, Volume 1, Third Edition.
Edited by Myer Kutz
Copyright 2006 by John Wiley & Sons, Inc.
of programmable rules, and produces the result as output.
Broken down into its two most fundamental components, a computer consists of the
physical machinery itself, known as the hardware, and the programs telling the computer
what to do, known as the software.
Computer hardware is simply a large amount of switches with the software controlling
how the switches should be set. The switches use values of 0 and 1 to represent whether
they are open or closed, and through this, a single unit of information can be stored in one
switch. This unit of information is known as a bit, which stands for ‘‘binary digit.’’ Typically
arranged into groups of eight, these eight bits make up one byte, which can hold 256 combinations,
or a number from 0 to 255.
These combinations of switches, however, are not limited only to representing numbers.
Based on the programmer’s preference, a particular combination of bits can represent a
specific number, letter, or even color for a graphics program.
Switches found inside a modern computer are not mechanical switches but electrical
ones that comprise a portion of a larger electrical circuit. The flow of electricity through
these switches is used to indicate the state of a switch and may, in turn, open or close other
switches. When enough switches are present, very complex calculations can be computed.
Within a modest modern computer, there are several million switches.
What is even more important than the sheer number of switches in a computer is the
speed at which these switches can be used. In a single second, one switch could turn on and
off more than a billion times, meaning that even complex tasks can be accomplished as fast
as the user can input the commands. This is possible because at the heart of these complex
commands are simple addition, subtraction, multiplication, and division commands utilizing
the switches as counters.
Beyond these switches, there are many other components that help to make up the entire
system. Broken down into its traditional components, the following are the hardware categories
you would find in a computer:
• Input Devices. Receive the information and instructions from the user and transfer
them into the computer.
• Memory. The array of switches that maintain an open or closed position until told to
change. This enables the computer to remember programs and information.
• Central Processing Unit. Where a majority of the calculations and processing of information
are completed utilizing a large array of switches.
• Output Devices. Display the results of programming after functions are performed.
• Storage. Maintains large amounts of information over a long duration of time.
Although this is the traditional breakdown of the components in a computer, these are
very ‘‘soft’’ boundaries, as can be seen with a floppy disk. In one instance, it can be seen
as an input device, delivering instructions to the computer. But in an entirely different instance,
it could be seen as an output device when data or programs are being written to it.
By the same token, there are also many devices that have fixed functions, such as the
keyboard and mouse being input devices.
The most basic form of software is known as the OS (operating system) and lies underneath
the most common software—those that are purchased or downloaded as special
applications. These applications are programmed to perform a specific task, such as word
processing or going onto the Internet. However, without the OS, these programs cannot run
because it is the OS that actually runs the computer.
However, beneath the OS resides the BIOS (basic input /output system), which instructs
the different components of the computer on how to communicate with each other. The
BIOS is typically embedded within the computer and is loaded immediately after the computer
is started.
COMPUTER-AIDED DESIGN
Emory W. Zimmers, Jr. and Technical Staff
Enterprise Systems Center
Lehigh University
Bethlehem, Pennsylvania
Mechanical Engineers’ Handbook: Materials and Mechanical Design, Volume 1, Third Edition.
Edited by Myer Kutz
Copyright 2006 by John Wiley & Sons, Inc.
