CPS 125: Digital Computation and Programming

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CPS 125 Digital Computation and Programming

• Week 1 Overview of Computers and Software

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Why do engineers study programming?

• Benefit
• from the ability to write their own programs
• Problems inevitably arise that are outside the
  range of problems solvable by the application
  software to which an individual
  engineer/scientist has immediate access.
• Critical
• Expanding societys technical knowledge
• Applying the principles of science and
  mathematics to societys problems, overlooking
  the limitations of a software

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Computer

• exists almost every where in our living
  environment
• From refrigerators, coffee machines, cars,
  stereos, mp3s, cell phones, boats, toys,
• A modern car contains about 50 microprocessors
• If you've got a late-model luxury sedan, two or
  three processors might be obvious in the GPS
  navigation system or the automatic distance
  control.
• The current 7-Series BMW and S-class Mercedes
  boast about 100 processors apiece.

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Computer in twenty-first century
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Important hint

• Learning programming is an essential to be a
  professional engineer for all fields.

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Outline

• What Is a Computer?
• Computer Components
• Computer Software
• Software Development Method

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What Is a Computer

• Computer
• An electronic machine that can receive, store,
• transform, and output data of all kinds
• numbers, text, images, graphics, and sound, to
  name a few.
• Conceptual Layers of a Computer System
• Application programs
• Operating system
• Computer hardware
• External connections

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What are Machine Structures?
Hardware

• Coordination of many levels of abstraction

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Computer Components
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Computer System

• CPU Main Memory core
• Secondary Storage I/O Devices peripherals
• Bus communication between components

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Central Processing Unit

• CPU the brain of a computer, transforms data
  from one to another, understands and executes
  computer programs written in machine language
• The circuitry of a modern CPU consists of
  millions of miniature circuits manufactured in a
  sliver of silicon known as Integrated Circuit
  (IC) or chip
• Microprocessor an entire CPU on a single chip
• Arithmetic operations are performed using binary
  number system where data and control information
  (instructions) uses only two basic symbols 0,
  1 represented by electronics signals

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Components of CPU

• Arithmetic/Logic Unit (ALU)
• performs arithmetic operations (addition,
  subtraction, etc.) and makes logical comparisons
  (and, or, equal to, etc.)
• Control Unit (CU)
• decodes machine instructions and sends control
  signals to the other components to carry out the
  instructions
• Registers
• high speed memory locations inside the CPU, used
  to store temporarily the current instructions and
  data values

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Question

• Which of the following statement is true?
• A). CPU Main Memory core of a computer
• B). The CPU consists of ALU,CU and Register
• C). CU decodes machine instructions and sends
  control signals to the other components to carry
  out the instructions
• D). Registers are high speed memory located
  inside the CPU
• E). All of the above

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Question 2

• The arithmetic and Logic Unit
• A). Decode instructions
• B). Perform decision making
• C). Performs arithmetic operations
• D). All of the above
• E). C and B above

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Binary Numbers

• All information in a typical computer is
  represented in binary
• Bits a binary digit (0 or 1)
• Bytes 8 bits of data, which is the amount of
  memory required to represent one character
• Conversion from binary to decimal
• b7 b6b5b4b3b2b1b0, where bi has place value 2i
• Convert to decimal
• b7 27b626 b525 b424 b323 b222 b121
  b020

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Example of Binary-Decimal Conversion

• 124 in binary
• Answer 01111100
• 251 ?
• 10101011 in decimal
• Answer 171
• 01101111 ? In Binary

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Negative binary numbers

• 2s complement notation
• In one's complement, positive numbers are
  represented as usual in regular binary. However,
  negative numbers are represented differently. To
  negate a number, replace all zeros with ones, and
  ones with zeros - flip the bits
• Begin with the number in one's complement. Add 1
  if the number is negative.

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True or false?

• Arithmetic operations are performed by CPU
  using binary number system

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Memory

• The main memory is used to store the program and
  data which are currently manipulated by the CPU
• The main memory is fast and of limited size
• The most common memory type is random access
  memory (RAM)
• The information stored in RAM will be lost when
  electrical power is removed
• ROM

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Memory Cells

• Memory a collection of memory cells
• Memory cell
• Memory cell can be randomly accessed

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Question

• Answer Ture/False
• Every byte in memory has a unique address to be
  accessed
• RAM stand for Random Access Memory
• can be read and written.
• ROM stand for Read Only Memory
• RAM is used to store application programs
• ROM is used to install System routines
• used for store the system BIOS and video BIOS

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Secondary Storage

• The secondary storage provides the long-term
  storage of large amounts of data and program
• Before data and program in the secondary storage
  can be manipulated by the CPU, they must first be
  loaded into the main memory
• The secondary storage is relatively slow and of
  very large size

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Secondary Storage Devices

• Magnetic Disks thin platter of metal or plastic
  on which data are represented by magnetized spots
  arranged in tracks
• Hard disks (attached to disk drives) many GB
• Floppy disks (removable) 1.44 MB
• Zip disks (removable) 100 or 250 MB

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Secondary Storage Devices

• Optical Disks silvery plastic platter on which a
  laser records data as pits in a spiral track on
  one side of disk
• CD 680 MB DVD 4.7 GB on one layer
• Magnetic Tape a sequential-access device (for
  backup of data)
• File named collection of data stored on disk
• e.g. c\compons\ics\cpus\pent.txt (PC)

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Data Storage Hierarchy
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Storage Capacity
Units Abbrev. Equivalent to Comparison to Power of 10
Byte B 8 bits
Kilobyte KB 1024 (210) bytes gt 103
Megabyte MB 220 bytes gt 106
Gigabyte GB 230 bytes gt 109
Terabyte TB 240 bytes gt 1012
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Input and Output Devices

• Provide interfaces for humans to communicate with
  computers
• Input devices
• Keyboards type into text
• Mouse, track balls, touch pads pointing devices
  for input of position/selection data
• Scanner convert image to a grid of pixels
• Output devices
• Monitor, printer, speaker, etc.

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Networks

• Groups of individual computers and peripheral
  devices linked together to share information and
  resources.
• Local Networks (LAN)
• Wide Area Networks (WAN)
• Internet
• Links machine throughout the world

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Connecting Computers LAN
computer
computer
computer
Local Area Network (LAN)
color printer
BW printer
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Connecting Computers WAN
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Computer Software

• Two Types of Software
• Operating System
• Application Software
• Computer Languages
• Machine Language
• Assembly Language
• High-Level Language
• From Source-Code to Executable Code

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Operating System

• Control and manage computer resources
• Main functions
• Communicating with computer users
• Managing allocation of computer resource
• Collecting input and conveying output
• Accessing and writing to secondary storage
• Authorization
• Widely used operating systems
• UNIX, Windows, Macintosh OS, and OS/2, etc.

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Application Software

• Application software is the software that has
  made using computers indispensable and popular
• Common application software
• Word processors
• Spreadsheets
• Database management systems
• Drawing programs
• Learning how to develop application software is
  our focus

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Computer Languages

• Machine Languages
• A collection of binary instructions
• Hard to understand by humans while the only
  understandable language by computers
• Specific to a particular type of CPU
• Assembly Languages
• Operations are represented by mnemonics,
  variables are represented by names, so is more
  readable
• Dependent on type of CPU

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Example of machine language code

• 000000 00001 00010 00110 00000 100000
• 100011 00011 01000 00000 00001 000100
• 000010 00000 00000 00000 10000 000001
• adding the registers 1 and 2 and placing the
  result in register 6
• Loading a value from the memory cell 68 cells
  after the one register 3 points to into register
  8
• Jumping to the address 1025

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Example of Assembly language code

• page 60,132
• TITLE A07LOOP (COM) Illustration of LOOP
• .MODEL SMALL
• .CODE
• ORG 100H
• A10MAIN PROC NEAR
• MOV AX,1 Initialize AX and
• MOV BX,1 BX to 1,
• MOV CX,10 CX for 10 loops
• INC AX Add 01 to AX
• A20 ADD AX,BX Add BX to AX
• MOV BX,AX
• LOOP A20 Decrement CX,
• loop if nonzero
• MOV AX,4C00H End processing
• INT 21H
• A10MAIN ENDP
• END A10MAIN

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Computer Language

• High-Level Language
• Closer to the human way of expression
• Using higher-level of abstraction concepts from
  the application area for which it is intended
• Independent of a given hardware
• The downside computers do not understand
  high-level languages

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High-Level Language
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Software Development Cycle
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Software Development Method

1. Specify the problem requirements
2. Analyze the problem
3. Design the algorithm to solve the problem
4. Implement the algorithm in a high-level computer
   language
5. Test and verify the completed program
6. Maintain and update the program

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An Example for Problem Analysis

• Problem statement
• Calculate and display the volume of a cylinder
  given its base radius and height in centimeters.
• Summarization
• Problem inputs
• Radius of base of a cylinder (in centimeters)
• Height of cylinder (in centimeters)
• Problem outputs
• Volume of cylinder (in cubic centimeters)
• Relationship between input and output
• The formula for the volume of a cylinder V p r2h

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Design

• Algorithm a list of instructions to solve a
  problem
• Top-down design
• List major steps, or sub-problems
• Solve the sub-problems
• Algorithm refinement
• Basic algorithm for a programming problem
• Get the data -gt Perform the computations -gt
  Display the results
• Desk check

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Implementation, Testing, and Maintenance

• Implementation writing it as a program, which
  means converting each step into one or more
  statements in a programming language
• Test testing the completed program to verify
  that it works as desired, with several runs and
  different sets of data
• Maintenance modifying program to remove
  undetected errors and to keep it up-to-date
• Caution Failure is part of the process

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Summarize

• What Is a Computer
• Computer Components
• Computer Software
• Software Development Method

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(No Transcript)
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Week1

• End