Introduction to Computers and Programming

Introduction to Computers and Programming

• A program is a set of instructions for a computer to perform a task.
• Programs are often called software.
• Software is essential for computers; without it, a computer cannot function.
• A programmer designs, creates, and tests computer programs.

Hardware

• Hardware refers to the physical components of a computer.
• A computer is a system of interconnected devices.
• Key hardware components include:
  • Central Processing Unit (CPU)
  • Main memory (RAM)
  • Secondary storage devices
  • Input devices
  • Output devices

CPU

• The CPU is the "brain" of the computer, responsible for running programs.
• Early CPUs were large, using vacuum tubes and switches.
• Modern CPUs (microprocessors) are small chips.
• Microprocessors are more powerful than their predecessors.
• The ENIAC was a significant early computer, being a large CPU.

Main Memory (RAM)

• RAM stores programs and data while the program is running.
• RAM is volatile; data is lost when the computer is turned off.
• RAM is often called random-access memory.

Secondary Storage Devices

• Secondary storage holds data long-term, even when the computer is off.
• Disk drives store data magnetically.
• External disk drives are used for backups and transferring data.
• Floppy disks are a less common, slow, and less reliable storage option.
• USB drives (flash memory) are compact, reliable, and inexpensive.
• Optical storage (like CDs and DVDs) use lasers to read/write data.

Input Devices

• Input devices collect data from users and external sources.
• Common input devices: keyboard, mouse, scanner, microphone, and digital camera.

Output Devices

• Output devices display or deliver data to users.
• Common output devices: video displays and printers.

How Computers Store Data

• All data in a computer is stored as sequences of 0s and 1s.
• Data is organized into small storage locations called bytes.
• Bytes are divided into smaller locations called bits.
• A bit represents either 0 or 1.

Storing Numbers

• A bit turned off represents 0; a bit turned on represents 1.
• Each bit position in a binary number has a value associated with it, based on powers of 2. (e.g., 2⁰, 2¹, 2², ...).

Storing Characters

• Characters are stored as binary numbers using numeric codes (e.g., ASCII, Unicode).
• ASCII assigns a numeric code to English letters, punctuation, etc.
• Unicode is a more expansive character encoding scheme.

ASCII Code Table

• The table lists the numeric codes for various characters.

How a Program Works

• Programs are sets of instructions in machine language.
• People use high-level languages to write programs, then special programs translate them to machine language for the CPU.

Fetch-Decode-Execute Cycle

• The CPU fetches instructions from memory.
• The CPU decodes the instruction to understand the operation.
• The CPU executes the operation.

From Machine to Assembly Language

• Assembly language uses mnemonics (short words) instead of binary.
• An assembler translates assembly language to machine language.

High-Level Languages

• High-level languages, like C, Java, Python make programming more accessible.
• They allow programmers to concentrate more on the tasks/problems at hand.

Compiler vs. Interpreter vs. Assembler

• A compiler translates the entire program at once.
• An interpreter translates and executes the program line by line.
• An assembler translates assembly language to machine language.

Software

• Software is categorized as either system software or application software.
• System software controls and enhances the operation of a computer.
• Application software makes a computer useful for everyday tasks.

System Software

• Operating systems manage computer hardware and software.
• Utility programs enhance computer operation or protect data.
• Software development tools are for program creation and testing.

This quiz covers the basics of computer systems, including the roles of hardware and software. Learn about the key components like the CPU and RAM, and understand how programs function within computer architecture. Test your knowledge of fundamental concepts in computing and programming.