This presentation discusses various computer input, output, and storage devices. It covers common input devices like keyboards, mice, microphones, and cameras. Output devices discussed include monitors, printers, and speakers. The central processing unit and memory are also summarized, including the CPU components like the ALU and control unit. Registers in the CPU and different types of computer memory are defined.

1. INPUT DEVICES PRESENTED
BY:
OUTPUT DEVICES
PRESENTED BY:
MEMOMY PRESENTED BY:
CPU PRESENTED BY:

2. In this presentation, we’ll discuss various input,
output, and CPU(central processing unit),memory
designed to meet the various needs and lifestyles
of people.

3. Input Devices Output Devices Storage Devices

4. • Input device captures information and translates it into a form
that can be processed and used by other parts of your computer.
Keyboards
Pointing devices
Game controllers
Scanners
Styluses
Microphones
Digital cameras
Web cams

5.  The keyboard is the most common input
device. Types of keyboards include:
• Wireless
• Multimedia and one-touch access
• Portable keyboards for PDAs

7.  Pointing devices are mainly used to choose and
enter commands
 Pointing devices tend to have PS/2 connectors or
USB connectors
• PS/2 connector fits into a PS/2 port, which a small round
socket with small holes that fit the pins on the connector
• USB connectors fit into USB ports, and these are small
rectangular openings on the back or front of your computer,
or even on your keyboard or monitor

8.  Various pointing devices are available
 Types of pointing devices:
• Mouse
Mechanical mouse
Optical mouse
Wireless mouse
• Trackball
• Touchpad
• Pointing stick

9.  Game controllers are used mainly to play games
 Types of gaming devices
• Gamepads
• Joysticks
• Gaming wheels
• Force feed

10.  Other types of input devices include:
• Scanners
• Styluses
• Microphones
• Digital cameras
• Web cams

11. •Scanner is a light sensitive device that helps you
copy or capture images, photos, and artwork
that exist on paper. Types of scanners include:
Flatbed

12. • Stylus is an input device consisting of a thin
stick that uses pressure to enter information
or to click and point
• Styluses are used with:
PDAs
Tablet PCs
Graphics tablets

13. • Microphones are used to
input audio
• Three main types of
microphones are:
Desktop microphones
Headsets
Directional microphones
• Speech recognition is
increasingly being included
in application software

14.  Digital cameras are used to:
• Download images to a computer
• Post pictures to the Web
• Produce videos
 Resolution is measured in
megapixels
 Higher the resolution, better the
image quality, but the more
expensive the camera

15. • Web cam is a video camera
that can be used to take
images for uploading to the
Web

16.  Output devices take
information within your
computer and present it to you
in a form that you can
understand
 Main output devices:
 Monitors
 Printers
 Speakers

17.  Devices with flat-panel displays
• Tablet PCs
• PDAs
• Cellular phones
• Desktop computers

18.  CRTs
 Flat-panel displays
 Gas plasma
 LCD (liquid crystal display)
 Passive matrix
 Active matrix
 Called TFT (thin film transistor)
 Separate transistor for every pixel

19.  Inkjet – most popular
 Makes images by forcing droplets
through nozzles
 Top speed is 20 pages per minute
 Laser
 Forms images using an electrostatic
process
 Prints between 3 and 30 pages per
minute

20.  Resolution of a printer is the
number of dots per inch (dpi) it
produces.
 Higher the resolution, better the
image, and usually the more costly
the printer

21.  Multifunction printer:
• Scan, copy, fax, and print
• Can be either inkjet or laser
• Cost less than buying
individual units
• Take up less desk space

22.  A speaker is a device that
produces computer output
as sound
 Speakers are common
devices in computer systems
Examples include:
• Built-in speaker
• Two-device set speakers
• Surround sound speakers

23.  ALU (arithmetic logic unit)
 Performs calculations and comparisons (data changed)
 CU (control unit): performs fetch/execute cycle
 Functions:
 Moves data to and from CPU registers and other hardware
components (no change in data)
 Accesses program instructions and issues commands to the ALU
 Subparts:
 Memory management unit: supervises fetching instructions and data
 I/O Interface: sometimes combined with memory management unit
as Bust Interface Unit
 Registers
 Example: Program counter (PC) or instruction pointer
determines next instruction for execution

25.  Small, permanent storage locations within the
CPU used for a particular purpose
 Manipulated directly by the Control Unit
 Wired for specific function
 Size in bits or bytes (not MB like memory)
 Can hold data, an address or an instruction
 How many registers does the LMC have?

26.  Use of Registers
 Scratchpad for currently executing program
 Holds data needed quickly or frequently
 Stores information about status of CPU and
currently executing program
 Address of next program instruction
 Signals from external devices
 General Purpose Registers
 User-visible registers
 Hold intermediate results or data values, e.g.,
loop counters
 Equivalent to LMC’s calculator
 Typically several dozen in current CPUs

27.  Program Count Register (PC)
 Also called instruction pointer
 Instruction Register (IR)
 Stores instruction fetched from memory
 Memory Address Register (MAR)
 Memory Data Register (MDR)
 Status Registers
 Status of CPU and currently executing
program
 Flags (one bit Boolean variable) to track
condition like arithmetic carry and overflow,
power failure, internal computer error

28.  Stores values from other locations (registers
and memory)
 Addition and subtraction
 Shift or rotate data
 Test contents for conditions such as zero or
positive

29.  Each memory location has a unique address
 Address from an instruction is copied to the
MAR which finds the location in memory
 CPU determines if it is a store or retrieval
 Transfer takes place between the MDR and
memory
 MDR is a two way register

30. ©2003 The McGraw-Hill Companies
Address Data

34.  Determined by two factors
1. Number of bits in the MAR
 LMC = 100 (00 to 99)
 2K where K = width of the register in bits
2. Size of the address portion of the instruction
 4 bits allows 16 locations
 8 bits allows 256 locations
 32 bits allows 4,294,967,296 or 4 GB
 Important for performance
 Insufficient memory can cause a processor to
work at 50% below performance

35.  DRAM (Dynamic RAM)
 Most common, cheap
 Volatile: must be refreshed (recharged with
power) 1000’s of times each second
 SRAM (static RAM)
 Faster than DRAM and more expensive than
DRAM
 Volatile
 Frequently small amount used in cache
memory for high-speed access used

36.  Non-volatile memory to hold software that is
not expected to change over the life of the
system
 Magnetic core memory
 EEPROM
 Electrically Erasable Programmable ROM
 Slower and less flexible than Flash ROM
 Flash ROM
 Faster than disks but more expensive
 Uses
 BIOS: initial boot instructions and
diagnostics
 Digital cameras