CISC 110
Day 1
Hardware, Algorithms, and Programming
Outline
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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)
byte 3021
byte 3022
byte 3023
byte 3024
byte 3025
byte 3026
byte 3027
byte 3028
byte 3029
byte 3030
byte 3031
byte 3032
byte 3033
11110000
10101100
11011010
00110101
01000001
10101010
01011101
00000000
11111111
11100010
10110101
00011011
01001111
2 byte memory location at
address 3021: could hold a
16-bit integer
4 byte memory location at
address 3024: could hold a
32-bit integer
1 byte memory location at
address 3030: could hold
one letter
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Memory Sizes
Memory
Conversion
1 bit
1 nybble
Either 1 or 0
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)
Program/Software
Electronic Computer
Recipe
Oven & Utensils
(Algorithm)
(Hardware)
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
ActionScript:
Memory:
var row = 5;
row
row = 8;
next
var next = row + 1;
next = next + 1;
s
val
var s = “hi”;
var val = 3.5;
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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
\t
\’
\”
\\
New Line
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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