Input,%20Process,%20Output

1
Input, Process, Output

• Supplemental Lecture Notes

2
Typical System

• Computer case
• Monitor
• Printer
• Speakers
• Modem
• Keyboard
• Mouse

3
Computer Components

• Power supply
• Hard drive
• Expansion card
• Expansion slot
• System board
• CD-ROM or DVD-ROM
• Floppy disk
• Drive bay
• Central Processing Unit (CPU)
• Random access memory (RAM)

4
Ports

• Ports are connectors at the back of a computer
  system that you use to plug in an external
  device. This allow instructions and data to flow
  between the computer and the device

5
Any Port in a Storm

• Parallel port 25 holes female connector LPT1
  printer or storage devices
• Monitor port
• Keyboard port
• Serial port 9 or 25 pins male connector COM1
  mouse or modem
• Game port
• Network port
• USB port
• 127 devices
• Printer, modem, joy stick
• Firewire

6
Input and Output

• Chapter 2

7
Input Devices

• Keyboards
• Mice
• Trackballs
• Pointing Devices

8
Printers

• Speed of a printer is measured in pages per
  minute (PPM). A higher speed represents faster
  output
• Resolution determines the quality of images
• A higher resolution results in sharper images
• Printer resolution is measured in dots per inch
  (dpi)
• 600 dpi is acceptable 1200 is better for images
• Resolution expressed with two numbers represents
  dots per inch across and down

9
Types of Printers

• Ink-jet has a print head that sprays ink through
  tiny nozzles onto a page
• 2 to 10 pages (ppm)
• 360 to 2400 dots per inch
• Color printers spray cyan, magenta, yellow and
  black to create different colors
• Laser-printer
• Works like a photo copier
• Speed of 4 to 16 pages
• Have a CPU
• 600 to 2400
• Memory 2mb to 8 Mb

10
Print Buffer and Spoolers

• Printer buffer section of memory printer stores
  information waiting to print
• Printer spooler program on your computer that
  stores information waiting to print
• Stores more information than the buffer
• One spooler for each connected printer

11
Monitors

• Video cards translate instructions from the
  computer into a form Most computes the monitor
  can understand
• require at least 2 mb of video card memory

12
Monitor Metrics

• The smaller the dot pitch, the crisper the image
• 0.28mm is acceptable
• Refresh rate is measured in hertz (Hz)
• Times per second computer redraws the image
• 72 Hz or more is acceptable

13
Communications

• Modems let a computer exchange information
  through telephone lines
• Speed of a modem determines how fast it sends and
  receives messages
• 56,000 bps (56 Kbps)
• V.90 standard receive 56K and send 33.6K
• Speed at which information flows depend on the
  quality of the phone line

14
High-speed Connections

• ISDN Integrated Services Digital Network
• Digital phone line
• 56 Kbps to 128 Kbps
• Cable Modem
• Same cable as TV
• 4000 Kbps
• DSL Digital subscriber line
• High speed digital phone line
• 1000 6000 Kbps

15
Scanners

• A scanner is a device that reads images and text
  into a computer
• Optical Character Recognition (OCR) software that
  places scanned text into a document that can be
  edited in a word processor
• Color depth is measured in bits and indicates the
  number of colors a scanner can detect

16
Resolution

• Resolution determines the amount of detail a
  scanner can detect
• Ranges from 600 dpi to 2400 dpi
• You usually dont need to scan at a higher
  resolution than a printer can produce or a
  monitor can display
• Most monitors are 72 dpi
• Printers vary

17
USB and Firewire

• High-speed ports that allow information to
  quickly transfer between a computer and an
  external device
• USB
• Supports up to 127 device
• USB 1.0 12 megabits per second
• USB 2.0 480 Mbps
• FIREWIRE
• 63 devices at 400 Mbps
• Can purchase Firewire expansion card

18
Processing

• Chapter 3

19
CPU (Central Processing Unit)

• Processes instructions, performs calculations,
  and manages the flow of information
• Performance
• CPU speed is a major factor in determining how
  fast a computer operates (faster the speed,
  faster computer operates)
• Measured in megahertz (MHz) A clock cycle relates
  to the clock that controls the timing in the
  microprocessor.
• For example, a 900MHz (megahertz) clocked
  microprocessor generates 900 million clock cycles
  per second.
• Each generation of CPU is more powerful than the
  one before. It's clock cycles are faster at a
  given speed

20
Processing

• The Central Processing Unit (CPU) is the main
  chip in a computer
• Processes instructions
• Performs calculations
• Manages the flow of information

21
Types of CPUs (Chips)

• Intel Pentium Processor
• Intel Celeron
• Needs of home machines
• AMD Athlon Processor
• Business and home use
• AMD Duron Processor
• Home use
• VIA Cyrix Processor
• Inexpensive CPU

22
Processing

• Random Access Memory Temporarily stores data
  inside a computer
• Constantly overwritten
• Measured in megabytes (MB)
• If you have limited memory or you have many
  programs open, your computer may need to use part
  of the hard drive to simulate more memory

23
Primary Storage

• Speeds up computer by storing data the computer
  has recently used
• Internal Cache On CPU chip (L1 or primary cache
• External Cache On the system board and consists
  of Static RAM (SRAM chips)
• Sometimes built into chip
• RAM slower main memory
• Each time the computer requests data from RAM,
  the computer places a copy of the data in memory
  cache
• Constantly contains the most recently used data

24
Using Memory

1. Look through documents on your desk (internal
   cache)
2. Look through documents in your desk drawer
   (external cache)
3. Looking through documents in your filing cabinet
   (RAM)
4. Go out and get it from the trunk of your car
   (secondary storage)

25
Math Coprocessors

• A special processing unit that assists the CPU in
  performing certain operations.
• A math coprocessor is a chip or part of a chip
  that specializes in doing math. Hardware that
  attaches to the motherboard or is part of the
  CPU.
• Also called numeric coprocessors or floating
  point units (FPU).

26
Storage Devices

• Chapter 4

27
Bus

• Electronic pathway that carries information
  between devices in a computer
• Bus Width (think lanes of a highway)
• 8 bits is one character
• Bus Speed (think speed limit)
• Measured in MHz (millions of cycles per second)

28
Hard Drives

• Magnetically stores data on rotating disks called
  platters
• Capacity is measured in bytes
• Speed is measured in revolutions per minute

29
Floppy Drives and Drives

• Removable media
• Can be write-protected
• Can be damaged magnetically

30
CD-ROM

• ROM (Read-only memory) - cant be changed
• 650 Mb of data
• Equal to entire set of encyclopedias
• 400 Floppy disks
• Speed determines how fast a disk spins
• Look for 24X
• Speed of CD-ROM drive is the transfer rate
• In Kb (e.g. 3600Kbs)

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CD-R CD-RW Drives

• CD-R (Compact Disc Recordable)
• Permanent store not erasable
• CD-RW
• Can be erased and rewritten
• Read / Write and Re-write speeds
• Usually 74 minutes
• Special software needed to record onto a disk
• Referred to as burning a CD

32
DVD-ROM Drive

• DVD Digital Versatile Disk
• Generally cannot change the information stored on
  a disk
• Similar to CD but stores more information
• Speed determines transfer rate (6 X)
• Capacity
• 1 side / 1 layer 4.7 GB
• 1 side / 2 layer 8.5 GB
• 2 sides / 1 layer 9.4 GB
• 2 sides / 2 layers 17 GB

33
Tape Drive

• Backup helps you copy files to tape cartridges
• Try to find a drive that can store the entire
  contents of your hard drive

34
Removable Storage Devices

• Jazz Drive 2 GB
• Zip Drive 250 MB
• LS-120 Drive 120 MB

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Operating Systems

• CPS120 Introduction to Computer Science

36
Operating Systems

• Software that controls the overall activity of
  the computer
• Ensure that all of the parts of the computer work
  together smoothly
• Functions
• Control hardware
• Run software
• Manage information
• Programs that run on one operating system
  platform do not generally run on others

37
Types of Operating Systems

• MS-DOS
• Command driven
• Windows
• Windows 3.1
• Windows 9X (95, 98)
• Windows ME
• Windows XP
• Windows NT
• Windows 2000
• UNIX
• MAC OS

38
Unix

• Can run single computer or entire network
• Developed on mainframes in late 60s
• True multi-tasking OS
• Most widely used operating system on Internet

39
LINUX

• Unix-based system offered as freeware on the
  Internet

40
Software

• CPS120 Introduction to Computer Science

41
Software

• System software runs the machine
• Application software helps you accomplish
  specific tasks
• Manufacturers also may create minor software
  updates called patches, to make corrections or
  improvements to software

42
Utility Programs

• Utility A program that performs a specific task
  on your computer
• Norton utilities recover files
• Virusscan anti-virus software
• Acrobat Reader View PDF (Portable Document
  Format) files
• Winfax pro
• ViaVoice Speech recognition
• WinZip Compress and decompress files

43
Application Software

• Word processor
• Spreadsheets
• Presentation Software
• Database Software
• Internet Software

44
Database Programs

• Helps you manage large collections of related
  information
• Uses
• Store information
• Find information
• Analyze and print information

45
Databases

• Organized in
• Tables
• Collection of information about a specific topic
• Field
• Category of information
• Record
• Single instance of information

46
Programming Languages

• CPS120 Introduction to Computer Science

47
Programming Languages

• A programming language is a set of rules that
  provides a way of telling a computer what
  operations to perform.

48
Levels of Programming Languages

• Machine language
• Assembly Language
• High Level Languages
• Fourth Generation Languages (4GL)

49
Machine Languages

• different for each computer processor
• 0100
• 001101 100000 001101 110001
• 00101 10001 10000
• 01110
• 111001
• . . .

50
Assembly Languages

• different for each computer processor
• main proc pay
• mov ax, dseg
• mov ax, 0b00h
• add ax, dx
• mov a1, b1
• mul b1, ax
• mov b1, 04h

51
High-Level Languages

• Higher Level Languages
• Use traditional programming logic where the
  programming instructions tell the computer what
  to do and how to perform the required operations.
• 4GLs
• Use high-level English-like instructions to
  specify what to do, not how to do it .

52
Types of Programming Languages

• Machine language
• Procedure-oriented languages
• Object-oriented languages
• Event-driven languages

53
What Can a Program Do?

• A program can only instruct a computer to
• Read Input
• Sequence
• Calculate
• Store data
• Compare and branch
• Iterate or Loop
• Write Output

54
Fundamental Programming Concepts

• Assignment of values to a variable
• Iteration (Looping)
• Over a set of set of statements
• With respect to a logical expressions
  (conditions)
• Delegation of sub-tasks to functions / procedures

55
The Structure Theorem

• The Structure Theorem states that any algorithm
  can be built from three basic control structures.
  
• One-after-another (Sequence)
• Decision-making (Selection)
• Making choices between 2 or more alternatives
• Repetition (Iteration)
• Concerned with repetitive tasks (and the
  termination conditions of loops)