lecture notes, #3

what binary numbers mean

how to convert from base 2 to base 10
how to convert from base 10 to base 2
octal, hexademical numbers to binary and back
base 8, base 16

how do we count in hex?
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F

0 - 0000
1 - 0001
2 - 0010
3 - 0011
4 - 0100
5 - 0101
6 - 0110
7 - 0111
8 - 1000
9 - 1001
A - 1010
B - 1011
C - 1100
D - 1101
E - 1110
F - 1111

Lecture HW#1:
1) Convert these decimal numbers to binary:
7
14
103

2) Convert these binary numbers to decimal:
11001
110
11
1101

3) Convert those numbers in part 2 to octal.
4) Convert those numbers in part 2 to hexadecimal.

programming languages
low-level languages
one very close to the actual instruction set of the CPU


00100010010100101100100000001111100101010
machine language

assembly language
mov ax, 4
mov bx, 3
add ax, bx

correspondence between assembly instructions and machine
mov 00100
ax 0001
bx 0010

http://en.wikipedia.org/wiki/Assembly_language

high-level languages
http://en.wikipedia.org/wiki/High-level_language

Some C++ code to calculate costs:
http://www.functionx.com/cpp/examples/ifelse1.htm
#include <iostream>
using namespace std;

void main()
{
    unsigned int Miles;
    const double LessThan100 = 0.25;
    const double MoreThan100 = 0.15;
    double PriceLessThan100, PriceMoreThan100, TotalPrice;

    cout << "Enter the number of miles: ";
    cin >> Miles;

    if(Miles <= 100)
    {
        PriceLessThan100 = Miles * LessThan100;
        PriceMoreThan100 = 0;
    }
    else
    {
        PriceLessThan100 = 100 * LessThan100;
        PriceMoreThan100 = (Miles - 100) * MoreThan100;
    }

    TotalPrice = PriceLessThan100 + PriceMoreThan100;

    cout << "\nTotal Price = $" << TotalPrice << "\n\n";
}

compiler
interpreter

Java, C++ compiled language
JavaScript, python