1. Output devices Convert from electronic form to some other form
May display the processed results
Usable information
Monitor or screen
Text
Numbers
Symbols
Art
Photographs
Video
Printer
Black and white
Color

2. Output Devices Monitor
Output devices make the information resulting from the processing available for use. The two output devices are as follows:
Printer
Monitor
The printer produces a hard copy of your output, and the computer screen produces a soft copy of your output.

3. Output Devices Monitor There are two basic types of monitors:
CRT (cathode ray tube) monitors
LCD (liquid crystal display) monitors.
Both types produce sharp images, but LCD monitors have the advantage of being much thinner and lighter. CRT monitors, however, are generally more affordable

4. Central Processing Unit (CPU)
The Processor
Central Processing Unit (CPU)
Converts data to useful information
Interpret and execute instructions
Communicate with input, output and storage

5. Motherboard The motherboard is the computer's main circuit board.
It's a thin plate that holds the CPU, memory, connectors for the hard disk drive and optical drives, expansion cards to control the video and audio, as well as various external ports and peripherals.
The motherboard connects directly or indirectly to every part of the computer.

6. Computer Memory
Computer Memory are internal storage areas in the computer .
used to either temporarily or permanently store data or instructions to be processed.

7. Flash Disk /Floppy Disk
Computer Memory
Memory
Internal Memory
Volatile Memory
RAM
Non-Volatile Memory
ROM
External Memory
Sequential Access
Tape Drive
Random Access
Compact Disk
Hard Disk
Flash Disk /Floppy Disk

8. Memory What are the two types of memory in the system unit?
Volatile Memory
Loses its contents when the computer's power is turned off
volatile memory
Loses its contents when the computer's power is turned off
nonvolatile memory
Does not lose its contents when the computer’s power is turned off

9. What is random access memory (RAM)?
Also called primary storage and main memory,
chips that temporarily holds software instructions and data before and after it is processed by the CPU.
RAM is the working memory of the computer.

10. What is read-only memory (ROM)?
Memory chips that contain data, instructions, or information that is recorded permanently
BIOS
(basic input/output system)
Stored on ROM
Sequence of instructions the computer follows to load the operating system and other files when you first turn on the computer
Data can only be read, cannot be modified
Nonvolatile — Contents not lost when the computer is turned off

11. Memory
Memory also called Random Access Memory or RAM (temporary memory) is the main memory of the computer. It consists of electronic components that store data including numbers, letters of the alphabet, graphics and sound. Any information stored in RAM is lost when the computer is turned off.
Read Only Memory or ROM is memory that is engraved on a chip that has start-up directions for your computer. It is permanent memory.

13. Two Types of Storage
Secondary storage
long-term storage
Primary storage or memory
temporary storage

14. Storage Devices Primary Storage Devices
Also known as internal memory and main memory.
The fastest type of memory in your computer and is used to store data while it's being used.
Computer RAM and cache are both examples of a primary storage device.
For example, when you open a program data is moved from the secondary storage into the primary storage.
Unless this information is saved to a Secondary Storage Device, it will be lost when the computer is powered down.

15. Storage Devices RAM (Random Access Memory)
Computer’s short-term memory.
Data is temporarily stored here until you save your work to the hard disk.
RAM is used by the system to store data that is processed by a computer's CPU.
RAM is a volatile memory and requires power; if power is lost, all data is also lost.

16. Secondary Storage Devices
Also known as external memory and auxiliary storage, secondary storage
Used to store data when they are not being used in memory.
The most common types of auxiliary storage used on personal computers are:
floppy disks, hard disks, CD-ROM drives, USB

17. Secondary Storage Devices
Floppy Disks
A portable, inexpensive storage medium that consists of a thin, circular, flexible plastic disk with a magnetic coating enclosed in a square-shaped plastic shell.
Initially Floppy disks were 8-inches wide, they then shrank to 5.25 inches, and today the most widely used floppy disks are 3.5 inches wide and can typically store 1.44 megabytes of data.

18. Structure Of Floppy Disks
Initially Floppy disks were 8-inches wide, they then shrank to 5.25 inches, and today the most widely used folly disks are 3.5 inches wide and can typically store megabytes of data.
A folly disk is a magnetic disk, which means that it used magnetic patterns to store data.
Data in floppy disks can be read from and written to.
Formatting is the process of preparing a disk for reading and writing.
A track is a narrow recording band that forms a full circle on the surface of the disk.

19. Structure Of Floppy Disks
The disk’s storage locations are divided into pie-shaped sections called sectors.
A sectors is capable of holding 512 bytes of data.
A typical floppy stores data on both sides and has 80 tracks on each side with 18 sectors per track.

20. Secondary Storage Devices
Hard Disks
Consists of one or more rigid metal plates coated with a metal oxide material that allows data to be magnetically recorded on the surface of the platters.
The hard disk platters spin at a high rate of speed, typically 5400 to 7200 revolutions per minute (RPM).
Storage capacities of hard disks for personal computers range from 10 GB to 120 GB.

21. Secondary Storage Devices
Compact Discs (CD)
Also called an optical disc, is a flat round, portable storage medium that is usually 4.75 inch in diameter.
Standard CD can hold 700MB of data, around 80minutes of CD quality audio, or up to 60minutes of video.
The later standard called the DVD (Digital Versatile Disc) is still an optical media much like the CD but with much greater capacities, starting at 4.7GB at the low end to as high as 17GB.

22. Secondary Storage Devices
USB Drive (Universal Serial Bus)
Also known as a flash drive or keychain drive.
It is a plug-and-play, portable storage device.
can be used in place of a floppy disk, Zip drive disk, or CD.
Available in capacities ranging up to about 65 GB.

23. Put all the hardware together and…

25. Types of Computers Supercomputer. Mainframe computer. Mini computer.
Depending upon their speed and memory size, computers are classified into following four main groups.
Supercomputer.
Mainframe computer.
Mini computer.
Microcomputer

26. Supercomputers
High-capacity machines with hundreds of thousands of processors that can perform over 1 trillion calculations per second.  E.g IBM ASCI White, Cray
Used where High Performance computing is required
Usually used for weather forecasting, Missile simulations, Nuclear Fusion simulations
Computers are listed in decreasing order of size.
Supercomputer - typically priced from $500,000 to more than $85 million, supercomputers are high-capacity machines with hundreds of thousands of processors that can perform over 1 trillion calculations per second.
Picture caption: IBM ASCI (Accelerated Strategies Computing Initiative) White
IBM ASCI White
IBM ASCI White

27. Mainframes
Water- or air-cooled computers that vary in size from small, to medium, to large, depending on their use.
E.g IBM AS/400
Normally Dumb Terminals are connected to these main frames. Processing is done by Main Frames
Dumb terminals only have keyboard, monitors
Mainframe - water- or air-cooled computers that cost $ $5 million and vary in size from small, to medium, to large, depending on their use.
Small mainframes used to be called minicomputers; today, they’re more frequently called midsize computers.
Terminal - means often used to access a mainframe. Consists of a display screen and a keyboard. A terminal can input and output data but cannot by itself process data.
VP2400 mainframe

28. Sun Microsystems workstation
Workstations
Expensive, powerful computers usually used for complex scientific, mathematical, and engineering calculations and for computer-aided design and computer-aided manufacturing.
e.g. Sun blade 2500
Workstations - expensive, powerful computers usually used for complex scientific, mathematical, and engineering calculations and for computer-aided design and computer-aided manufacturing.
Sun Microsystems workstation

29. Microcomputers A Desk Top Personal Computer
Your home computers… Celeron
Now Desktop and Workstations are combining. i.e Your PC is also becoming powerful enough
Microcomputers - also called personal computers. Cost $500 - $ Can fit next to a desk or on a desktop, or can be carried around.
Tower PC - PC in which the case sits as a “tower,” often on the floor beside a desk, thus freeing up desk space.
FACTOID: Some computer manufacturers produce PCs called “mini-towers.”
Local area network (LAN) - a network connecting, usually by special cable, a group of desktop PCs and other devices, such as printers, in an office or a building.

30. Microcomputers A Tower Case Personal Computer Sony tower PC
Microcomputers - also called personal computers. Cost $500 - $ Can fit next to a desk or on a desktop, or can be carried around.
Tower PC - PC in which the case sits as a “tower,” often on the floor beside a desk, thus freeing up desk space.
FACTOID: Some computer manufacturers produce PCs called “mini-towers.”
Local area network (LAN) - a network connecting, usually by special cable, a group of desktop PCs and other devices, such as printers, in an office or a building.
Sony tower PC

31. Microcomputers A Lap Top Personal Computer
Lightweight portable computers with built-in monitor, keyboard, hard-disk drive, battery and AC adapter.
Microcomputers - also called personal computers. Cost $500 - $ Can fit next to a desk or on a desktop, or can be carried around.
Tower PC - PC in which the case sits as a “tower,” often on the floor beside a desk, thus freeing up desk space.
FACTOID: Some computer manufacturers produce PCs called “mini-towers.”
Local area network (LAN) - a network connecting, usually by special cable, a group of desktop PCs and other devices, such as printers, in an office or a building.

32. Microcomputers A Personal Digital Assistant Getting Very popular
Personal organization tools-schedule planners, address books, to-do lists, send and faxes.
New generation that incorporates mobile phone and microcomputer.
HP 5555
Microcomputers - also called personal computers. Cost $500 - $ Can fit next to a desk or on a desktop, or can be carried around.
Tower PC - PC in which the case sits as a “tower,” often on the floor beside a desk, thus freeing up desk space.
FACTOID: Some computer manufacturers produce PCs called “mini-towers.”
Local area network (LAN) - a network connecting, usually by special cable, a group of desktop PCs and other devices, such as printers, in an office or a building.

33. Thank You