Download Input Hardware

Input Hardware and Connector Types
August 23 (Day); August 22 (Night)
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Information Processing Cycle:
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For your computer to perform any task, it must go through a series of four steps
known as the information processing cycle. These four steps include input,
processing, output, and storage.
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The computer’s information processing cycle is almost identical to the way we, as
human beings, process information. For example, you ask a friend to add the
numbers two plus two and write the answer on a piece of paper.
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Input – you actually saying the numbers two plus two
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Processing – friend’s mental calculation of the answer
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Output – friend’s writing the number four to saying the number aloud
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Storage – piece of paper with a number four written on it
Hardware can be classified on the basis of which step it performs on the information
processing cycle:
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Input – keyboard, mouse
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Processing – CPU
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Output – monitor, printer
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Storage – memory (a.k.a. RAM), hard drive
Here’s another rule of thumb for relating the information processing cycle to
hardware. Most input (keyboard, mouse) and output (monitor, printer) devices are
outside the computer. Most processing (CPU) and storage (memory, floppy disk
drive, hard disk drive) devices are found outside the computer case.
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Binary Numbering System:
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When you sit at the computer, you communicate with it by providing words and
numbers as input. This input cannot be understood directly by the computer’s
hardware.
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Every communication that software has with hardware is done as one of two states.
This format is known as binary.
o
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On – represented numerically by 1 or electrically by one voltage.
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Off – represented numerically by 0 or electrically by a different voltage.
Each instance is of one of these states is known as a bit. A group of eight bits is
known as a byte.
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Three Requirements of Hardware:
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A way for the device to communicate with the CPU.
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Software to instruct and control the device.
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Electricity to power the device.
Input Hardware:
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Port:
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Input and output devices communicate with the processor and storage
devices inside the computer case through cables attached to the case at a
connection called a port (p. 12).
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Most ports are located on the back of the computer case.
Computer Ports
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Peripheral Device:
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Virtually everything attached to the computer is typically referred to as a
peripheral device (p. 11).
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Most input and output devices are considered peripheral devices (p. 11).
Keyboard:
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The most common keyboard today has 104-keys – 101 keys as well as 3
Windows keys (p. 321).
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The standard keyboard connects to the computer through a 6-pin connector
known as a PS/2 connector (p. 14).
PS/2 Connector Pinout
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Keyboard Port
Every computer comes with a driver already built into the system that will
run a standard keyboard (p. 325).
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Electricity to power the keyboard from inside the computer case and is
provided by wires in the keyboard cable.
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More recently, keyboards have begun to be made for the USB port and
wireless (pp. 322-323).
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Mouse:

A mouse is a pointing device used to move a pointer on the screen on an X
and Y axis (p. 326).
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Like the keyboard, a standard mouse uses a round 6-pin connector known as
the PS/2 connector (p. 14).
PS/2 Connector Pinout
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Mouse Port
Every computer comes with a mouse driver built in. Most mice have
customized drivers to take advantage of special features (p. 329).
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More recently, like keyboards, mice have begun to be made for the USB port
and wireless (p. 328).
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Other mice:

The trackball is a standard-issue mouse turned upside down (p.
326).

An optical mouse uses a tiny camera that detects mouse
movement by taking images of the surface that the mouse moves
over (p. 327).
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Game Controllers:
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Game controllers come in three main types: joysticks, steering/racing wheels,
and game pads (p. 330).
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Most game controllers connect to the 15-pin female port named as a serial
port (p. 331).
15-pin Serial Port
15-pin Serial Port Pinout
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Most operating systems have drivers built-in for the serial ports. Most game
controllers use more advanced drivers (p. 331).
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Recently, many game controllers have moved to USB (p. 331).
External Connectors:
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DB Connector:
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DB connectors have a slight D-shape.
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DB connectors consist of either small pins (a.k.a. male) or sockets (a.k.a.
female).
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DB connectors are identified in the following manner. For example, a game
port is a 15-pin male DB connector. It would be identified as DB15M.
o
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DIN Connector:
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DIN connectors are round.
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The mini-DIN is used for PS/2 connectors such as mouse and keyboard.
RJ Connector:
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An example of a RJ connector would be your telephone jack.
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An RJ-11 jack is a phone jack and used for modems.
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An RJ-45 jack is wider and used for network cabling.
RJ-45, RJ-11 Connector
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Audio Connector:
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Speakers and microphones plug into what are known as mini-audio
connectors.