Introduction to Computers

What is a computer?

What does a computer do?

Power of a Computer• Speed• Reliability• Bits and Bytes• Accuracy• Storage

Process

Storage

Input

Output

Raw Data

Information

Computer Components

CPU – Central Processing Unit

• Control Unit and Arithmetic /Logic Unit

• Memory - – ROM

• Read Only• BIOS • Remains on power off

– RAM• Random access• Empties on shut off

Input Devices

• Keyboard• Mouse• Magnetic Card• Scanner• Stylus• Touch Screen• Card Scan• Biometric

Out Put Devices

• Monitor– CRT– LCD

• Printer– Impact / dot matrix– Inkjet– Laser

• Speaker

Computer Storage

• Floppy Disk – 1.4 MB• Hard Disk - Gigabytes• CD

– CD ROM, CD-R, CD-RW– 650 MB

• DVD – 4.7-17 GB

Data Size

Bit 1,0

Byte 11010110 = 1 character

Kilobyte - KB 1000 bytes

Megabyte - MB 1million bytes

Gigabyte – GB 1 billion bytes

Memory

• RAM – random access memory– Stores information temporarily– Like the desktop or workbench– Data is erased on powerdown

• ROM – read only memory– In the CPU and other places– Remains the same – rarely changed– Remains upon powerdown

Software

• System Software – controls the operation of the computer

• Must boot up to start – loads operating system into memory

• GUI – graphical user interface – DOS– Windows, 3.11, 98, ME, XP,

XP Pro, 2000

Application Software

• Application Software – software that tells the computer how to produce information – office– games– finance– diagnostic– business– utilities – anti virus, pop up blockers, etc.

Word Processing Software

• MS Word, Corel…• For working with

text• Easy to make

changes / corrections

• Combines with other software

Spreadsheet Software

• Calculations• Charts• Eliminates

recalculation• MS Excel

Database Software

• Stores Data of all kinds for easy access

• MS Access, Schoolmaster,

• Produces reports of the information

• Law Enforcement

Networks and the Internet

• Network– Computers linked

together– Sharing of hardware,

software, data, information

• LAN – local area network

• WAN – wide area network

• Internet

Internet / WWW

• World’s largest network

• Web Pages• Web Site• URL – uniform

resource locator – unique address