Unit II: Number Systems, OS, and Programming Tools
Course: Fundamentals of Information Technology
Code: CADSC101
Number Systems
Number systems are the mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner.
Common Bases
- Binary (Base 2): Uses 0 and 1.
- Octal (Base 8): Uses digits 0 to 7.
- Decimal (Base 10): Uses digits 0 to 9.
- Hexadecimal (Base 16): Uses digits 0-9 and letters A-F.
Conversion of Bases
Computers convert all human-readable data into binary for processing. Conversion involves dividing (from decimal) or multiplying (to decimal) by the target base.
[Image of Number system conversion chart]
Character Representation and Codes
Specific coding schemes are used to represent characters and numbers in a format the computer can understand.
- BCD (Binary Coded Decimal): Each decimal digit is represented by a fixed number of binary bits.
- ASCII (American Standard Code for Information Interchange): A standard code for representing text in computers.
- EBCDIC: An 8-bit character encoding used mainly on IBM mainframe.
- Gray Code: A binary numeral system where two successive values differ in only one bit.
Operating System (OS)
Definition: An Operating System is a system software that acts as an interface between the user and the computer hardware.
Functions of an Operating System
- Process Management: Managing execution of multiple programs.
- Memory Management: Allocating and de-allocating memory space.
- File Management: Keeping track of files stored on storage devices.
- Device Management: Controlling input and output devices through drivers.
[Image of Operating System functions diagram]
Types of Operating Systems
OS can be categorized based on how they process tasks.
- Batch OS: Jobs are collected in batches and processed together.
- Multi-programming OS: Multiple programs run on a single processor simultaneously.
- Time-sharing OS: Allows multiple users to use the computer at the same time.
- Real-time OS: Used where time constraints are very strict (e.g., missiles, medical).
Windows vs. Linux
These tools translate high-level code into machine language.
- Assembler: Translates Assembly language to Machine code.
- Compiler: Translates the whole program at once.
- Interpreter: Translates the program line by line.
- Linker: Links various object files to create an executable.
- Loader: Loads the executable into memory for execution.
Algorithms and Flowcharts
Before writing a computer program, a logical plan is created.
- Algorithm: A step-by-step procedure to solve a problem.
- Pseudo-code: Informal description of an algorithm using plain English.
- Flowchart: Graphical representation of an algorithm using symbols.
Exam Focus & Tips
- Exam Tip: Practice Binary to Hexadecimal conversions; they are guaranteed marks.
- Common Mistake: Thinking an Interpreter and Compiler are the same. Remember: Compiler = Whole; Interpreter = Line-by-line.
- Mnemonics: B-O-D-H for Number Systems (Binary, Octal, Decimal, Hex).
Frequently Asked Questions
Q: What is the base of Hexadecimal?
A: 16 (Digits 0-9 and A-F).
Q: Define a Linker.
A: It is a tool that combines multiple object files into a single executable file.