Introduction to Computer Science (CSC 111)

Introduction to Computer Science (CSC 111) Lecture Notes

• Lecture Overview: The lecture will cover computer software, operating systems, application packages, exercises, and assignments.

Computer Software

• Definition: Software is a computer's set of programs. These programs provide instructions for the computer to perform tasks. They are the instructions given to the computer, and a collection of them make up software.

Types of Software

• System Software: Programs that run computer hardware and application software.

  • Examples: Operating systems (like DOS, Windows XP, Vista, Unix/Linux, macOS), utility software (file management like Windows Explorer, compression tools, virus protection, disk tools, etc). Language Processors (compiler, interpreter, assembler).

• Application Software: Programs that handle specific tasks for users.

  • Examples: Word processing (e.g., Ms. Office 2003, 2007), graphics programs (e.g., Macromedia Dreamweaver, Flash, Freehand, Adobe PageMaker, Photoshop), specialized software (school management systems, inventory management, payroll systems, financial systems).

Operating System

• Definition: A platform that manages and coordinates resources for a computer, handling interaction between the user and hardware.
• It hosts the numerous programs running, regulating and managing their sharing of hardware resources.

Functions of an Operating System

• Processor Management: Controls how the CPU and other processors are used.
• Memory Management: Manages how RAM is used by programs.
• File Management: Manages how files are stored and accessed.
• Device Management: Controls how input/output devices (the keyboard, mouse, monitor, printers, etc.) work.

Types of Operating Systems

• Real-time Operating System (RTOS): Aims to execute real-time applications. Used in critical systems that need timely responses (nuclear power plants, oil refining, chemical processing, traffic control).
• Single User Systems: Designed for single user at a time. Most desktop operating systems fall into this category (Example: DOS).
• Multi User Systems: Support multiple simultaneous users. Often found in mainframes or time-sharing systems. (Example: Unix)
• Multi-tasking and Single-tasking: Multi-tasking systems allow multiple programs to run at once, whereas single-tasking systems only run one program at a time.
• Distributed Operating System: Manages a group of independent computers, making them appear as one. Allows distributed computing, better performance, is easily scalable and offers resource sharing

Commonly Used Operating Systems

• UNIX: Popular multi-user, multi-tasking operating system created in the early 1970s, using C programming language and able to be used on many systems.
• LINUX: A free and open-source OS based on Unix. This allows use on many platforms such as personal computers and Macintoshes.
• Windows: A series of graphical operating systems by Microsoft, introduced in late 1985 (as an enhancement to MS-DOS), that dominates personal computer market.
• Solaris: Unix-based OS, originally by Sun Microsystems, now owned by Oracle after their acquisition.
• BOSS (Bharat Operating System Solutions): A GNU/Linux distribution by C-DAC (Centre for Development of Advanced Computing), for enhancing open source software use, placing particular emphasis on desktop security features.

Utility Software

• Definition: Programs that manage, maintain, and control computer resources. Operate at the lower level to handle issues and management not covered by the operating system.

Application Packages

• Types: Word processing, spreadsheets, databases, presentations.
• Custom/User Software: Programs developed to address specific user requirements.

Assignment Questions

• These questions cover topics for assignments:
  • Most recent Android version?
  • Short note on Windows.
  • Most recent mobile Windows Phone version?
  • Operating System Function details.
  • Differences between open-source and proprietary software.