CISC 110 Day 1

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CISC 110Day 1

• Hardware, Algorithms, and Programming

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Outline

• Structure of Digital Computers
• Programming Concepts
• Output Statements
• Variables and Assignment Statements
• Data Types
• String and Numeric Operations

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Structure of Digital Computers
I/O Devices Input/Output Devices (e.g. Keyboard,
Mouse, Webcam) Communication between the computer
and the user, and with other computers
Main Memory RAM (Random Access Memory)
Short-term memory of data and programs, while
computer is powered on
CPU (Central Processing Unit) Calculations and
the Fetch-Execute Cycle
Secondary Storage Long-term memory of data and
programs (e.g. hard drive)
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Main Memory (RAM)
11110000 10101100 11011010 00110101 01000001 1010
1010 01011101 00000000 11111111 11100010 10110101
00011011 01001111
byte 3021
2 byte memory location at address 3021 could
hold a 16-bit integer
byte 3022
byte 3023
byte 3024
4 byte memory location at address 3024 could
hold a 32-bit integer
byte 3025
byte 3026
byte 3027
byte 3028
byte 3029
1 byte memory location at address 3030 could
hold one letter
byte 3030
byte 3031
byte 3032
byte 3033
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Memory Sizes
Memory
Conversion
1 bit
Either 1 or 0
1 nybble
4 bits
1 byte
8 bits
1 kilobyte
210 bytes (approx. 1000 bytes)
1 megabyte
220 bytes (approx. 1000 kilobytes)
1 gigabyte
230 bytes (approx. 1000 megabytes)
1 terabyte
240 bytes (approx. 1000 gigabytes)
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Computers A Definition

• Computers are machines that can carry out routine
  mental tasks by performing simple operations at
  high speeds (operations built into the hardware
  machine operations).

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A Definition of an Algorithm

• An algorithm is a sequence of instructions that
  describes how to carry out a task.

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A Mathematically Precise Definition of an
Algorithm

• An algorithm is a finite sequence of unambiguous,
  executable instructions for carrying out a task
  or process in a finite amount of time.
  
• Note This assumes no intelligence on the
  part of the user. The intelligence and knowledge
  of a person is encoded in the algorithm.

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A Definition of a Programming Language

• A programming language consists of a repertoire
  of possible instructions, each of which can be
  specified in terms of the simple operations
  (machine operations) a computer can execute.

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Cake-making Computation
Bit String Numbers or Characters Cake
Ingredients (Input)
Electronic Computer Oven Utensils (Hardware)
Program/Software Recipe (Algorithm)
Bit String Numbers or Characters Cake (Output)
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A Definition of a Scripting Language

• A scripting language is a programming language
  that allows control of an application, for
  instance an animation.
• The name script is derived from the written
  script of the performing arts, which tells the
  actors what to say.

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ActionScript Trace()

• Purpose To display values in the output panel
  to trace the state of an animation
• Examples
• trace( 525 )
• trace ( Now starting love scene )
• trace ( Row 5 Col 7 )
• trace ( 5 7 )
• trace ( 5 7 5 7 )

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Defining Variables to Store Values
Memory
ActionScript
var row 5 row 8 var next row 1 next
next 1 var s hi var val 3.5
row
next
s
val
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Data Typing Variables
ActionScript var row int 5 row 8 var
next int row 1 next next 1 var s
String hi var val Number 3.5
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String Operations

• Operators
• Concatenation
• Append
• Escape Sequences
• \n New Line
• \t Tab
• \ Single Quote
• \ Double Quote
• \\ Backslash

Examples trace( Hey you ) trace(
Hey\nyou ) trace( Hey\tyou ) trace(
Hey\you\ )
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Arithmetic Operations

• Operators
• Addition
• - Subtraction
• Multiplication
• / Integer Division
• Mod
• (integer remainder of division)

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Imperative Programming

• Statements
• Variable Assignment ()
• Branching (if, else)
• Loops (while, for)
• Data Structures
• Integers
• Strings
• Arrays
• Classes
• Functions

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