Plymouth State University Computer Hardware How to Choose a Multimedia Computer

Plymouth State University

Computer Hardware

How to Choose a Multimedia Computer


ENIAC - The FirstElectronic Digital Computer


The Four Functions of a Computer

INPUT

PROCESSINGOUTPUT

STORAGE INFORMATION

DATA


The System Unit

Power Supply

System Board

Hard DrivesorCD-ROM Drives

Floppy Drive

Expansion Card


Directions of Computer Development

• Miniaturization– Transistors– Integrated circuits

• Solid state

• Semiconductor

• Chip


Integrated Circuit

• IC, or "chip"

• Made from Silicon

• Includes Transistors, Resistors & Capacitors


Steps in Manufacture of a Microchip

1 Make large drawing. Reduce drawing hundreds of times to microscopic size.

2 Duplicate reduced photo many times on sheet.


Etched Silicon Wafer


Future Developments in Processing & Storage

• Moore’s Law– Gordon Moore predicted the number of transistors

on a silicon chip will double every 18 months– It has held up since the 1960s!


The System Unit: The Basics

• The CPU– Older CPUs processing speeds are in MegaHertz

• 1 MHz = 1 Million ticks per second

– Current CPUs processing speeds are in GigaHertz• 1 GHz = 1 Billion ticks per second

– The faster a CPU runs, the more power it consumes, and the more heat it generates


Secondary Storage, Primary Storage and the CPU

Main Memory(RAM)

CPUSecondary Storage

(Disk)

Load

Execute


How Memory Works: RAM, ROM, & Flash

• Types of memory chips:

1. RAM - Random Access Memory, used to temporarily hold software instructions and data

2. ROM

3. Flash


How Memory Works: RAM, ROM, & Flash


1. RAM

2. ROM - Read-Only Memory, which cannot be written on or erased by the computer user. Contains fixed start-up instructions

3. Flash


How Memory Works: RAM, ROM, CMOS, & Flash


1. RAM 2. ROM 3. Flash - can be erased and reprogrammed

more than once


Bits & Bytes

• Kilobyte

• Megabyte

• Gigabyte

• Terabyte

• Petabyte


Binary Coding Schemes

• ASCII

• EBCDIC

• Unicode


Microchips

• Microprocessors

• Memory

• Logic

• Communications

• Graphics


Central Processing Unit

Control Unit Arithmetic/Logic Unit Registers


CU ALU

CPU

Registers


Control Unit

Controls step-by-step operation of computer


Arithmetic/Logic Unit

Arithmetic 2 + 4 = 6 10 - 6 = 4

Logic 9 > 6 3 < 7 5 = 5


Registers

• Temporary storage locations within the CPU


CPU Operation

Machine CycleTime it takes to process one machine instruction

Two parts:• Fetch Cycle - Get instruction, decode it, set up• Execution Cycle - Carry out the instruction


TOTAL = 13 + 12

CUALU

Registers

CPU


TOTAL = 13 + 12

CUALU

CPUADD


TOTAL = 13 + 12

CUALU

CPU

13

ADD


TOTAL = 13 + 12

CU

ALU

CPU

13

12

ADD


TOTAL = 13 + 12

CUALU

CPU

13

12

25

ADD


TOTAL = 13 + 12

CU ALU

CPU

13

12

2525TOTAL

Main Memory

STORE


Two Types of Storage

• PRIMARY Storage - Main memory or RAM

• SECONDARY Storage - Auxiliary Storage (disks, Flash etc.)


Disk Drives

Drive A:“Floppy” DRIVE

Drive C:Hard Drive(Internal)


Secondary Storage DevicesHard Disks

• Nonremovable disks– Known as a fixed disk– Capacity up to 1 terabyte +– Consists of 4 - 3.5 inch metallic platters


Hard Disk Drive


Magnetic Disk Uses Direct Access

1 5 6

3 2

4 7


Magnetic Disk Storage

Rotational Delay

Seek Time


Disk Heads

Hair

Dust

Magnetic Disk Surface

Read/WriteHead


Head Crash

Read/WriteHead

Disk Surface


Compact Disk (CD)


Secondary Storage DevicesOptical Disks

• CD – compact disk– about 700 megabytes – CD-ROM– CD-R– CD-RW


Secondary Storage DevicesOptical Disks

• DVD – digital video disk– 4.7 – 17 gigabytes– DVD-ROM – read-only– DVD-R – rewritable one time– Reusable types

• DVD-RW• DVD-RAM


Flash Memory

Flash memory is nonvolatile


Input and Output

INPUT - We provide the DATA to be processed

OUTPUT - We use the INFORMATION produced


Input & Output Hardware

Input hardwareTranslates words, numbers, sounds, and

pictures into numbers

Output hardwareTranslates numbers back into words, numbers,

sounds, and pictures


Some Input Devices

• Keyboards• Pointing devices

• Mouse• Trackball

• Touch screen• Pen input• Source data-entry devices

• Scanner• Text (OCR)• Voice• Video• MICR• FAX


Input Hardware

• Keyboards: convert letters, numbers, and characters into electrical signals– English keyboards differ from foreign language

keyboards

German Keyboard


Input HardwareWebcams and Video-input Cards

• Webcams– Video cameras attached to a computer to

record live moving images then post them to a website in real time

– Require special software, usually included with the camera


Input HardwareCamera Phones

• Digital cameras are now on cell phones– Convenience of being able to take photos, then

instantly email or message them to someone else


Touch Screen


Input HardwareSource Data-Entry Devices

• Scanning devices – imaging systems

• Scanning devices – bar code readers– Magnetic-ink character recognition (MICR)– Optical-mark recognition (OMR)– Optical character recognition (OCR)

• Scanning devices – fax machines


Check Processing

9999999 12345687


Source Data-Entry Device


Bar Code


Smart Cards

Similar to credit cardsContain a microprocessor


Digital Camera


GPS


Biometrics

• Fingerprints

• Retina Scanning

• Face Recognition


Output Hardware

• Softcopy– Data that is shown on a display screen or

is in audio or voice form; exists electronically

– Output that is ephemeral in nature

• Hardcopy – Printed and film output– Output that is more permanent in nature


Display Screens


ResolutionResolution

..................................

Resolution = TOTAL PIXELS = # dots across by # dots down

Example: 1024 X 768


Types of Terminals

• Dumb Terminals

• Intelligent Terminals


Specialized Terminals ATM’s

POS’s


MIDI Music


Output Hardware:Hardcopy Devices

• Impact printers– Dot-matrix

• Nonimpact printers– Laser– Ink-jet


Other Types of Output

• Projectors

• COM

• Machine Control

• Voice

• House Control Center


Machine Control


Health Matters

• Repetitive stress injuries– Carpal tunnel syndrome

• Eyestrain & headaches

• Back & neck pains

• Electromagnetic fields

• Noise


Ergonomics

• Fitting the job environment to the worker

• Purpose – make working conditions and equipment safer and more efficient


Ergonomic Considerations

• Chair

• Keyboard Height

• Wrist Rest

• Monitor Height

• Lighting

• Noise


Ergonomic Keyboard


Ergonomics

• Eye strain

• Radiation

• Glare


Ethics

• Theft

• Counterfeiting

Craig’s List

72 Web Expressions

Documents

Plymouth State University Computer Hardware How to Choose a Multimedia Computer