CSBP119 Algorithms Chapter 1

Study Notes

Computers are designed to execute a set of instructions known as programs, which are essential for tasks like word processing or presentations.
Software refers to all programs that enable a computer to perform its functions.
Programmers or software developers create, design, and test these programs.

Hardware comprises the physical components of a computer, working in tandem as a system.
Major hardware components include:
- Central Processing Unit (CPU): executes programs and is critical for software operation.
- Main Memory (RAM): temporary storage for programs running and data in use, characterized as volatile memory.
- Secondary Storage: retains data long-term, with types including Hard Disk Drives (HDD), Solid State Drives (SSD), and Flash memory.
- Input Devices: components used to collect data from users (e.g., keyboard, mouse).
- Output Devices: formats and presents data from the computer (e.g., monitors, printers).

The CPU is the primary component that processes instructions, crucial for running software.
Microprocessors are a compact version of CPUs, found on small chips.

Data in computers is represented as binary sequences (0s and 1s).
A byte is the smallest data unit, consisting of eight bits, and can hold a character or small number.
Bits represent two values: 0 and 1; binary system uses positional values to calculate numeric representation.
ASCII (128 characters) and Unicode (more comprehensive, supports multiple languages) are standard coding systems for characters.

The CPU performs operations by fetching instructions from memory, decoding them, and executing them in a constant cycle.
Programs need to be loaded from secondary storage to RAM for execution.

Machine language is not user-friendly; thus, assembly language simplifies programming using mnemonics.
High-Level Languages, such as Python, allow for easier program creation without needing detailed CPU knowledge.
Key aspects when writing programs in high-level languages include:
- Keywords: predefined terms with specific meanings.
- Operators: perform operations on data (e.g., arithmetic).
- Syntax: rules for constructing valid statements.

High-level languages require translation into machine language for execution.
Compilers convert the entire program into machine language for later execution.
Interpreters, like those used in Python, translate and execute code line by line, providing immediate feedback.

Python requires installation, including the interpreter, for programming.
Python can be used in two modes:
- Interactive Mode: users input statements directly; useful for learning and testing.
- Script Mode: users save commands in a file with a .py extension, executed via command line (e.g., python filename).

Errors encountered during the coding process are indicated, with syntax errors preventing code translation into machine language.
Interactive mode offers immediate feedback, aiding in correcting mistakes.