Week 4 Lecture (Pages 44-61)

• Presenter: Francisco G. Recote II, MSCS (Sir "Iko")

INFORMATION TECHNOLOGY APPLICATION TOOLS IN BUSINESS

CLASSIFICATION OF COMPUTERS

Based on Operating Principles

• Digital Computers: Operate by counting with discrete numbers, useful for arithmetic and data manipulation.

• Analog Computers: Use continuously changing physical quantities to model problems (e.g., electrical, mechanical).

• Hybrid Computers: Combine features of both analog and digital computers, using digital components for control and analog components for solving differential equations.

Based on Area of Application

• General Purpose Computers: Designed for a wide range of applications.

• Special Purpose Computers: Designed for specific tasks.

Based on Size and Capability

• Desktops: Stationary computers.

• Portables: Computers that can be easily transported; include laptops, notebooks, palmtops, and wearable computers.

Desktop Computers

• Microcomputers (Personal Computer): Smallest in size for general-purpose use.

• Minicomputers: More powerful than microcomputers, medium-sized.

• Workstations: High-performance machines used for applications like CAD/CAM, desktop publishing, etc.

• Mainframe Computers: Large, powerful computers with high-speed processing and storage capacity.

• Supercomputers: Extremely powerful computers, measured in millions of instructions per second (MIPS).

Based on Number of Microprocessors

• Sequential Computers: Use one microprocessor to complete tasks in sequence.

• Parallel Computers: Use multiple microprocessors to perform tasks simultaneously, offering high speed and reduced cost compared to supercomputers.

Based on Number of Users

• Single User: One user per resource at a time.

• Multi User: Shared computer resources for multiple users.

• Network: Interconnected autonomous computers shared by multiple users simultaneously.

NUMBER CONVERSION

Types of Number Systems

• Non-positional Number Systems: Use symbols with fixed values regardless of position (e.g., Roman numerals). Arithmetic operations are difficult.

• Positional Number Systems: Use symbols (digits) whose value depends on their position (e.g., decimal, binary). The base determines the maximum digit value.

Common Number Systems

• Base 2 (Binary): Symbols 0 and 1.

• Base 8 (Octal): Symbols 0-7.

• Base 10 (Decimal): Symbols 0-9.

• Base 16 (Hexadecimal): Symbols 0-9 and A-F for values 10-15.

Base Definition

• The base is the total number of digits in a number system; maximum single digit value = base - 1.

Characteristics of Decimal Number System

• Positional, base 10. Commonly used in daily life; example: 2586: (2x10^3) + (5x10^2) + (8x10^1) + (6x10^0) = 2586.

Characteristics of Binary Number System

• Positional, base 2, only uses 0 and 1. Commonly used in computers.

NUMBER SYSTEM CONVERSION TECHNIQUES

Binary to Decimal Example

• Calculation: (1x2^4) + (0x2^3) + (1x2^2) + (0x2^1) + (1x2^0) = 16 + 0 + 4 + 0 + 1 = 21.

Binary to Octal Example

• Example: Convert 1101010₂ to octal by grouping binary digits and converting.

• Result: 1101010₂ = 152₈.

Binary to Hexadecimal Example

• Example: Convert 1111012 to hexadecimal by grouping into fours and converting.

• Result: 111101₂ = 3D₁₆.

Octal to Binary Example

• Convert each octal digit to binary and combine.

• Result: 562₈ = 101110010₂.

Decimal to Octal Example

• Example: Convert 952₁₀ to octal through division by 8.

• Result: 952₁₀ = 167₈.

Hex to Binary Example

• Convert each hexadecimal digit to a 4-digit binary number.

• Result: 2AB₁₆ = 001010101011₂.

Base Conversion Example from Base 6 to Base 4

• Convert from base 6 to base 10, then from base 10 to base 4.

• Result: 545₆ = 310₄.

THANK YOU!