CSc 1253 section 3

1
CSc 1253 section 3

• Computer Science I with
• INSTRUCTOR Dr. Douglas
• www.austinlinks.com/ CPlusPlus/

2
First Day- CSC 1253

• Welcome
• Syllabus
• Introduction to Computers Background before the
  Programming!
• include ltiostreamgt
• main()
• cout ltlt "Hello World!"
• return 0

3
Introduction to Computers

• the Internet and the WWW
• Email
• Network/networking/networked Connected
  computers
• Operating Systems Microsoft, Unix
• Software - Word, PowerPoint, Excel, etc.
• Fun stuff - Games, Photos, etc.

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Introduction to Computers

• Computer System Hardware
  Software news.thomasnet.com/
  fullstory/454230/264

• Physical Components
• Input Devices
• Output Devices
• Primary Memory
• Auxiliary Storage
• CPU

Software Collection of programs usually in
executable form. ProgramA finite sequence of
instructions that the computer follows to
perform a specific task or solve a problem.
5
Introduction to ComputersHardware

• (1) Input Devices Receiving section of the
  computerAccepts data(?) from the outside
  worldStores data to memory
• Ex. keyboard, mouse, camera, microphone
• www.primidi.com/ 2004/11/29.html

6
Introduction to ComputersHardware

• (2) Output DevicesShipping section of the
  computerTakes info from memory and places
  that info on various output devices.Allows
  people to view/hear the results of
  processing. Printer (hard
  copy) Monitor
• (soft copy)
• Speaker

7
Introduction to ComputersHardware

• (3) Memory or RAM (Primary Memory)Provides rapid
  access fast retrieval
• of data (could be software instructions)Random
  ly Accessible Memory

www.computermemoryupgrade.net/ computer-memory...
? Memory components Plug into slots
? Connected to the
Systemboard (Motherboard)
8
Introduction to ComputersHardware

• (3) Memory continued www.fotosearch.com/
  ART158/tot008/ Temporary storage of data
  Volatile will lose it if not saved!Purpose
• 1. Holds info received from an input device.
  (Data is waiting to be processed.)
• 2. Holds software for execution.
• 3. Holds intermediate results from processing.
• 4. Holds data for output.
• The von Newmann Architecture

9
Introduction to ComputersHardware

• (3) Memory continuedMemory is divided into
  storage locations called memory
  cells.Associated with each memory location are
  1. Address - position of a cell in memory
• 2. Contents - info stored
• www.jegsworks.com/Lessons/ lesson4/lesson4-5.htm

10
Introduction to ComputersHardware

• (3) Memory continued
  www.kbcc.cuny.edu/
  propre/math/Math_13/
• Everything is manipulated as 0s and 1s
• stored using two-state devices switches,
  transistors, vacuum tubes.
• On/Off states easily compare to the binary
  numbering system, Base 2.
• On 1, Off 0 Binary Digit Bit

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Introduction to ComputersHardware
Data stored in 1 byte

• (3) Memory continuedBits are grouped into
  bytes ( 8 bits 1 byte)Each Memory Cell is
  1 byte Bytes are grouped into words (length
  is dependent on the machine)
• The computer handles data in multiples
• of bit chunks (bytes)
• Jpeg www.geog.ucsb.edu/kclarke/
  G128/Lecture05.html

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Introduction to ComputersHardware

• (3) Memory continued
• How data
• is stored
• Numbering
• Systems
• claymore.engineer.gvsu.edu/.../ html/plcs.html

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Introduction to ComputersHardware

• (3) Memory continued
• How data is stored Integers
• Convert Any Base to Base 10
• --- EXPAND ---
• Using
• Exponential Notation

1110012 _?_10 1 25 32 1 24
16 1 23 8 0 22 0 0 21 0 1 2
0 1 -------
5710
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Introduction to ComputersHardware

• (3) Memory continued
• How data is stored Integers
• Convert Any Base to Base 10
• --- EXPAND ---

FB416 _?_10 F 15, 15 162 3840 B
11, 11 161 176 4 4, 4 160
4 -------
402010
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Introduction to ComputersHardware

• (3) Memory continued How data is stored
  Integers
• Convert Base 10 to Any Base
• ---- DIVIDE BY THE BASE ----

• Example 5710 _?_2
• 57/2 28 r 1 ? 1
• 28/2 14 r 0 ? 0114/2
  7 r 0 ? 001
• 7/2 3 r 1 ? 1001
• 3/2 1 r 1 ? 11001
• 1/2 0 r 1 ? 1110012

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Introduction to ComputersHardware

• (3) Memory continued
• How data is stored Integers
• Convert Base 10 to Any Base
• ---- DIVIDE BY THE BASE ----
• Example 5710 _?_8
• 57/8 7 r 1 ? 1
• 7/8 0 r 7 ? 718

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Introduction to ComputersHardware

• (3) Memory continued
• How data is stored Integers
• Convert Base 10 to Any Base
• ---- DIVIDE BY THE BASE ----
• Example 6010 _?_16
• 60/16 3 r 12 1210 C16 ? C
• 3/16 0 r 3 3 316 ? 3C16
  

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Introduction to ComputersHardware

• 3) Memory continued How data is stored
• Base 2 to Base 8 Base 16 Neat Trick!

Base 2 to Base 8 1001101112
4 6 7 4678
Base 2 to Base 16 1110110112
1 D B 1DB16
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Introduction to ComputersHardware

• (3) Memory continued
• How data is stored Real
• Cannot represent exactly!
• 0.7 0.10110011001100112
• and that leads to Roundoff or Truncation
  http//wofford.info/ecs/ScientificProgramming/Erro
  r/images/Sec3Pic2.gif

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Introduction to ComputersHardware

• (3) Memory continued
• How data is stored characters
• (a, b, c, d, e, , A, B, C,, 1, 2, 3, !, _at_,
  , )
• Cannot be stored directly as a character. Remembe
  r 0s and 1s only.
• A code system is used ASCII, EPCDIC, UNICODE
• Each character is assigned a
• unique numeric value A ? 6510, y ? 12110

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Introduction to ComputersHardware

• Where are we?

• Physical Components
• Input Devices
• Output Devices
• Primary Memory
• Auxiliary Storage
• CPU

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Introduction to ComputersHardware

• (4) Auxiliary Storage
• http//www.infopackets.com/graphics/harddriveex
  posed2.gif, http//www.spygadgets.com/images/CD2
  0drive202.jpg, http//www.sthcross-c.schools.nsw.
  edu.au/students/assets2/memory20stick.jpg,/www.nu
  ggetlab.com/comptia_files/equipment/multimedia_Iom
  ega20Zip20Drive.jpg
• Stores data for permanent(?) keeping.Slower
  access for retrieval and storage than for
  primary memory. unlimited quantity -- Virtual
  Memory

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Introduction to ComputersHardware

• (5) Central Processing Unit CPUThe Brain,
  the microprocessor, the chip
• Controls the fetch/execute cycle fetch
  instruction, decode the instruction, executes
  the instruction.
• Contains Registers for storage
• inside the CPU fasssst access
• http//www.gamepc.com/images/labs/rev-tigermpx-768
  LG.jpg www.cs.sun.ac.za/ museum/gen4.html,

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Introduction to ComputersHardware

• (5) Central Processing Unit CPU continued
• Contains the Arithmetic Logic Unit (ALU)
• performs
• calculations, comparisons
• or makes decisions.
• http//www.cse.dmu.ac.uk/bb/Teaching/ComputerSyst
  ems/WorkStations/CPU.gif

Registers
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Introduction to Computers

• Computer System Hardware
  Software

• Physical Components
• Input Devices
• Output Devices
• Primary Memory
• Auxiliary Storage
• CPU

Software Collection of programs usually in
executable form. ProgramA finite sequence of
instructions that the computer follows to
perform a specific task or solve a problem.
26
Introduction to ComputersSoftware

• 2 Types of Software (executable program(s) )1.
  Application Software software that performs
  tasks
  for a computer user. Two types General-Purpos
  e Software purchased from a software
  developer ex. Excel, Word, Oracle
• Application-Specific Software Used only for
  its intended purpose and http//images.goog
  le.com/images?hlenlrqturbotax perhaps for
  a single user.
• www.ccatech.com/ ccatech/reviews/

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Introduction to ComputersSoftware

• Types of Software (executable program(s) )
  continued
• 2. Systems Software software that performs
  tasks required for operations of the computer
  system.
• Three Types
• Operating System provides services such as
  a user interface,
• file and database access, provides
  communication interfaces, manages programs in
  execution, directs low-level control of
  devices.
• System Support Software provides system
  utilities Ex. sort programs, disk format
  programs, provides operating
  statistics.
• System Development Software Convert
  programs into machine language form for
  execution.
•  

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Introduction to ComputersSoftware

• Programming Language
• A formal definition of a language that consists
  of both1. Syntax rules to determine how the
  symbols of the language
• may be combined.2. Semantics the meaning of
  the constructs.

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Introduction to ComputersSoftware
3 Types of Programming Languages

• Machine Language
•     Coded in 0s or 1s only Bit patterns
  represent command codes such as
• 0100 0000 0000 0101
• 1000 0000 0000 0110
• Machine dependent (platform dependent) because
  the patterns of the 0s and 1s have meaning
  only for a particular machine or type of
  computer.
• Programming is difficult and tedious
• May be printed in hexadecimal (Hex) or octal
  to be easily read.

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Introduction to ComputersSoftware
3 Types of Programming Languages continued

• Symbolic Language (Assembly Languages )
•   English-like abbreviations are substituted for
  the machine language.
• Load A
• Add B
•    Requires a translator to convert to
  machine language (ML).

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Introduction to ComputersSoftware
3 Types of Programming Languages continued

• High Level LanguageMay combine many of the ML
  steps into one.Some memory details hidden.
  Descriptive names for memory use.Uses common
  English and math notations.Language is
  portable.Requires a compiler to convert to
  MLEx. FORTRAN, C, PASCAL, COBOL, JAVA

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Introduction to ComputersSoftware

• Compiler
• software which translates a program written
  in a higher-level language (source program)
• into a program written in
• machine language (object program).

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Introduction to ComputersSoftware

• How Instructions are Stored in Memory
• End Hardware and Software Overview

0100 0000 0000 0101 1000 0000 0000 0110 1001 0000
0000 1000 0100 0100 0000 0100
LOAD A ADD B MULT C STORE X
X (A B) C
High Level Language
Machine Language
Assembly Language
Translator
Compiler
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Introduction to ComputersTerms

• Networking - Time Sharing EnvironmentIn the old
  days, a large computer called a mainframe was
  connected to dumb terminals. The mainframe
  possessed all the computing capabilities.
  Terminals were used like typewriters.
• 
  www.microsoft.com/.../ unix/usecdirw/01wsdsu.mspx

The Central Computer
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Introduction to ComputersTerms

• Networking - Client/Server Environment
  Work is shared (or removed) between the
  central computer and the workstation. The central
  computer is called a server.

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Introduction to ComputersTerms

• MSC
• Multiprogramming several programs are in memory
  at one time. Allows
• computer resources to be used more efficiently.
  Programs may be halted
• while resources are accessed and other programs
  in memory may then execute.
• Multiprocessors computers that have more than
  one CPU. Allows more than
• one program to execute simultaneously.
• Execution CPU executes program instructions
  on input data to generate
• program output.
• File data or code or whatever stored for
  access using a name.
• Ex. a data file for input Employee.dat
  (not executable)
• Ex. a report file that is the result of
  processing Report.out (not executable)
• Ex. an assembler for translating to machine
  code tasm.exe (executable)
• Ex. my granddaughters picture - birthdaypic.jpg
  (not executable)
• Ex. a program ready to be compiled
  prog1.c (not executable)
• End Terms

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Introduction to ComputersCreating Software for
Execution

• Step 1 Write and edit the program by creating a
  file using an ASCII text editor.A text
  editor is an executable program (software)!
• Text editors store character data only and a
  very few control characters like new line
  control.
• Ex. pico, or notepad
• This is called the source file.

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Introduction to ComputersCreating Software for
Execution

• Step 2 Compilation. Convert source file to
  another file into low level format (the object
  code) necessary for execution. The object code
  file is created using a Compiler.
• Step 3 Linking. Combine other object code with
  my object code. The linker program combines or
  links the separate files together to create a
  single executable file in ML form!

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Introduction to ComputersCreating Software for
Execution

• Step 4 Load ML file into memoryThe loader is
  system OS software that loads the program to be
  executed into primary memory.
• Step 5 Execution. Operating System gives the go-
  ahead and off we go. Program is now running.

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Introduction to ComputersCreating Software for
Execution

• Work Review
• Step 1 Write and Edit
• Step 2 Compilation
• Step 3 Linking
• Step 4 Load into Memory
• Step 5 Execution
• All files ?

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Introduction to Computers

• The End
• Next, the Software Development Method