Bits
and Bytes
The memory capacity of a typical
computer runs from hundreds of thousands to millions of bytes.
The terms bit and byte are common
in computer networking. Both terms refer to digital data transmitted over a
network connection. For example, bits and bytes both may represent network
addresses or port numbers.
BIT is the basic unit
of information, and it is a simple digit of a binary number.
In the computer BIT is physically a
transitor in a memory cell, as high or low voltage pulse
Through a circuit.
The groups of bits form storage
units inside the computer called BYTES
BYTE is the basic unit
of storage, used in micros up to mainframe. Computers work with collections of
8 bits.
A BYTE has the equivalent of only
one character, as in the letter “A”, the symbol “$” or a punctuation mark.
KB, MB
& GB
These
abbreviations means:
KB =
Kilobyte = about 1,000(one thousand) bytes,(1024 or 2^10)
MB =
megabyte = about 1,000,000(one million) bytes,(1,048,576 or 2^20)
GB =
gigabyte = 1,000,000,000 (one billion ) bytes (1,073,741,824 or 2^30)
As you can see, these abbreviations
stand for a specific number of bytes. And each bytes. Holds 8 bits capable of
forming 256 combinations of 1/10.
The number that comes before one of
these abbreviations represents the computer’s memory capacity. For example, if
a computer has 64MB of RAM that means that the computer can
handled 64,000,000(64 million) bytes of random acces memory (that´s 64,000,000
microscopic 8-bit panels).
Hard disk space is also measured in
bytes. So, a 15GB hard drive has 15,000,000,000
(15 billion) bytes for storing
memory.
Finally, bits can be used to code
pictures. Therefore, tiny dots called pixels have certain numbers of bits
assigned to them. Pictures are formed by putting many pixels together.
THE
BASIC PARTS OF THE COMPUTER
The most elementary parts of
computer are: the processor, the main memory, the keyboard, the speaker, the
screen, the disk drive, the printer, usb port, external hard disk, webcam.
THE PROCESSOR
It carries out sequences of
instructins or programs, stored in a sectionof the main memory of the computer.
THE MAIN MEMORY
It is the place where the computer
stores programs when it is running them. The portion of main memory not
occupied by currently running programs, is available for sotring information
entered at the keyboard or other information entered at the keyboard or other
information that information that the program is working on.
THE KEYBOARD
In computing, a keyboard is an
input device, wich uses an arrangement of buttons or keys, to act as mechanical
levers or electronics switches. A keyboard typically corresponds to a single
written symbol. However, to produce some symbols requires pressing and holding
several keys simultaneously or in sequence.
THE SPEAKER
It is used for sound effects, for
example a beep to indicate a successful start up or an unrecognized command.
The speaker can also produce musical tones.
THE SCREEN
A computer monitor is an electronic
device that shows pictures. A monitor is usually used to see programs on a
computer. The main difference between a monitor and a television is that a
monitor does not have a television if it is connected to a device that has a
television tuner. Some models of monitor can be used as a television, and some
televisions are used with computers. A monitor has a better display
resolution than a television to make it easier to see smaller letters and
graphics on.
THE PRINTER
It is a peripheral device used to
show the output of a processed program in shape of letters, numbers or
graphics printed on sheets of paper.
THE WEBCAM
As webcam is a video capture device
connected to a computer or computer network, often using a USB port. The most
popular use is for video telephony, permitting a computer ti act as a
videophone or video conferencing station. Other popular uses, which include the
recording fo video files or even still-imaes, are accessible via numerous
software programs, applications and devices.
The term “webcam” may also be used
in its original sense of a video camera
THE USB PORT
US(Universal Serial Bus) is a
specification to establish communication between devices and a host
controller(usually personal computers). USB is intended to replace many
varieties of serial and parallel ports. USB can connect computer peripherals
such as mice, keyboards, digital cameras, printers, personal media
players , flash drives, and external hard drives.
EXTERNAL HARD DISK
An external hard disk drive is a
type of hard disk drive widh is connected to a computer by a computer by a USB
cable or other means.
HOW TO
CONNECT TO THE INTERNET
If you
want to connect to the internet, you need specific equipment such as a
computer with multimedia and special programs that are provided by a company.
Depending
on what is available in your area, you can choose from two primary types of
connections: Dial-up or Broadband.
The
former is slow and the latest is faster, but for both you need to connect your
computer to a modem using a phone line.
The
fastest Dial-up connection transmit data at 56.6kbps (kilobits per second) wich
os okay forn normal web surfing but is not fast enough for downloading music or
videos.
THE
SERVICE PROVIDER
Many
providers give you hours or day or month for a set fee and if you exceed this
number of hours you will pay extra hours
BroadBand
Cable is connected in your normal cable television line providing speeds in the
500kbps to 30Mbps depending on the provider.
Broadband
Satellite Any household or business with a clear line of sight to the southern
sky can receive digital data signal from 1Mbps to 5Mbps.
The
popular DIRECTV digital satellite system enables you to receive internet signal
via small dish that you mount outside your house or on your roof.
GETTING
HELP
Getting
up a connection to an Internet Service Provider can be difficult. Find out if
the provider offers customer support in the evenings and on weekends as well as
during business time.
Web
pages can be created to share information with people around the world and the
providers let you publish and maintain web page for free.
FEATURES
The
companies that give Online Service include daily news, stock quotes, weather
reports, encyclopedias, dictionaries, etc.
The
public spaces of internet are free of a censorship. Setting up a connection to
an online service is easy because the companies provide the costumer
support for his question.
“Chatting”
is a very popular feature on online services; people can get connected by
simply typing back and forth, in order to meet people to exchange ideas.
When you chat, the text you type immediately appears on the screen of
each person involved in the conversation.
INTRODUCTION
TH NETWORK
A
network is a group of computers linked together, that permits users to share
not only software applications, but also hardware like printer, fax. There are
two types of network.
LAN
- LOCAL AREA NETWORK
A LAN
connect network devices over a relatively short distance. A networked office
building. School, or home usually contains a single LAN, through sometimes one
building will contain a few small LANs and occasionally a LAN will span a group
of nearby building.
In
addition to operating in a limited space, LANs are also typically owned,
controlled, and managed by a single person or organization.
WAN –
WIDE AREA NETWORK
WAN
spans a large physical distance. The internet is the largest WAN, spanning
the earth. A network device called router connects LANs to WAN.
A WAN
differs from a LAN in several important ways. Most WANs (like the
internet are not owned by any one organization but rather exist under
collective or distributed ownership and management.
THE
TOUCHSCREEN
is an
electronic visual display that the user can control through simple or
multi-touch gestures by touching the screen with one or more fingers. The user
can use the touchscreen to react to what is displayed and to control how it is
displayed (for example by zooming the text size).
The
touchscreen enables the user to interact directly with what is displayed,
rather than using a mouse, touchpad, or any other intermediate device (other
than a stylus, which is optional for most modern touchscreens).
Touchscreens
are common in devices such as game consoles, all-in-one computers, tablet
computers, and smartphones. They can also be attached to computers or, as
terminals, to networks.
Historically,
the touchscreen sensor and its accompanying controller-based firmware have been
made available by a wide array of after-market system integrators, and not by
display, chip, or motherboard manufacturers. Display manufacturers and chip
manufacturers worldwide have acknowledged the trend toward acceptance of
touchscreens as a highly desirable user interface component and have begun to
integrate touchscreens into the fundamental design of their products.
There
are a variety of touchscreen technologies that have different methods of
sensing touch.
RESISTIVE
A
resistive touchscreen panel comprises several layers, the most important of
which are two thin, transparent electrically-resistive layers separated by a
thin space. These layers face each other with a thin gap between. The top
screen (the screen that is touched) has a coating on the underside surface of
the screen. Just beneath it is a similar resistive layer on top of its
substrate. One layer has conductive connections along its sides, the other
along top and bottom.
SURFACE
ACOUSTIC WAVE
Surface
acoustic wave (SAW) technology uses ultrasonic waves that pass over the
touchscreen panel. When the panel is touched, a portion of the wave is
absorbed. This change in the ultrasonic waves registers the position of the
touch event and sends this information to the controlador for processing.
Surface wave touchscreen panels can be damaged by outside elements.
Contaminants on the surface can also interfere with the functionality of the
touchscreen
CAPACITIVE
A
capacitive touchscreen panel consists of an insulator such as glass, coated
with a transparent conductor such as indium tin oxide(ITO). As the human body
is also an electrical conductor, touching the surface of the screen results in
a distortion of the screen'selectrostatic field, measurable as a change in
capacitance. Different technologies may be used to determine the location of
the touch. The location is then sent to the controller for processing.
CONSTRUCTION
There
are several principal ways to build a touchscreen. The key goals are to recognize
one or more fingers touching a display, to interpret the command that this
represents, and to communicate the command to the appropriate application.
In the
most popular techniques, the capacitive or resistive approach, there are
typically four layers:
Top
polyester coated with a transparent metallic conductive coating on the bottom
Adhesive
spacer
Glass
layer coated with a transparent metallic conductive coating on the top
Adhesive
layer on the backside of the glass for mounting.
When a
user touches the surface, the system records the change in the electrical
current that flows through the display
BLUETHOO
Teclado bluetooth enlazado a un
computador de bolsillo.
Un auricular para teléfono móvil por
Bluetooth.
Bluetooth es una especificación
industrial para Redes Inalámbricas de Área Personal (WPAN) que
posibilita la transmisión de voz y datos entre diferentes dispositivos mediante
un enlace por radiofrecuencia en la banda ISM de los 2,4 GHz. Los principales
objetivos que se pretenden conseguir con esta norma son:
Facilitar las comunicaciones entre
equipos móviles y fijos.
Eliminar los cables y conectores entre
éstos.
Ofrecer la posibilidad de crear
pequeñas redes inalámbricas y facilitar la sincronización de datos entre
equipos personales.
Los dispositivos que con mayor
frecuencia utilizan esta tecnología pertenecen a sectores de las
telecomunicaciones y la informática personal, como PDA, teléfonos
móviles, computadoras portátiles, ordenadores personales, impresoras o cámaras
digitales.
TECHNICAL INFORMATION
La especificación de Bluetooth define un canal de comunicación a
un máximo 720 kbit/s (1 Mbit/s de capacidad bruta) con rango óptimo de 10 m
(opcionalmente 100 m con repetidores).
Opera en la frecuencia de radio de 2,4 a 2,48 GHz con amplio
espectro y saltos de frecuencia con posibilidad de transmitir en Full Duplex
con un máximo de 1600 saltos por segundo. Los saltos de frecuencia se dan entre
un total de 79 frecuencias con intervalos de 1 MHz; esto permite dar seguridad
y robustez.
La potencia de salida para transmitir a una distancia máxima de 10
metros es de 0 dBm (1 mW), mientras que la versión de largo alcance transmite
entre 20 y 30 dBm (entre 100 mW y 1 W).
Para lograr alcanzar el objetivo de bajo consumo y bajo costo se
ideó una solución que se puede implementar en un solo chip utilizando circuitos
CMOS. De esta manera, se logró crear una solución de 9×9 mm y que consume
aproximadamente 97% menos energía que un teléfono celular común.