Computer Science Notes

Covers the fundamentals of computer organisation, including the CPU (ALU, CU, Registers), memory hierarchy (RAM, ROM, Cache, Storage), the System Bus, mobile system organisation (SoC), and types of software (System Software, Application Software, and Software Libraries).

Covers digital number systems (Decimal, Binary, Octal, Hexadecimal), conversions between all four systems, and character/string representation using ASCII, ISCII, and Unicode encoding standards, including the UTF-8 and UTF-32 encodings.

Covers the fundamentals of binary logic, operations, and truth tables used in digital systems. It introduces Boolean variables and the three primary logic gates (AND, OR, NOT), alongside secondary gates like NAND, NOR, XOR, and XNOR. The chapter details Boolean algebra laws—including De Morgan's Laws—and demonstrates how to simplify complex expressions and design logic circuit diagrams.

Introduces Python — its history, pluses and minuses, how the interpreter runs code (bytecode and PVM), compiler vs interpreter, IDLE, Interactive Mode vs Script Mode, and your first program with print().

Character Set, Tokens, Keywords, Identifiers, Literals, Operators, Variables and Assignments, Simple Input/Output.

Covers Python data types (int, bool, float, complex, str, list, tuple, dict, None), mutable vs immutable types, all operators with precedence and associativity, expressions, implicit and explicit type conversion, the math module, and types of errors.

Covers the steps of problem solving, algorithms and their characteristics, flowcharts and pseudocode, the three control structures (sequence, selection, repetition), verifying algorithms with dry runs, comparing algorithms, coding and decomposition.

Covers statement types and pass, indentation, if, if-else, if-elif-else and nested if, the range() function, for and while loops, break and continue, the loop else clause, and nested loops with pattern programs.

Covers string indexing and immutability, traversing a string, the +, *, membership and comparison operators, slicing with negative indices and steps, built-in string methods (case, search, checking, strip, replace, split, join, partition), and important string programs.

Covers creating lists, indexing and mutability, list operations and slicing, traversal, aliasing vs copying, list functions and methods (append, extend, insert, pop, remove, index, count, sort, reverse, sorted), nested lists, and programs for max/min/mean, linear search and frequency counting.

Covers creating tuples (including single-element tuples), indexing, immutability, tuple operations and slicing, packing and unpacking, tuple functions and methods, nested tuples, list vs tuple, and programs for max/min/mean, linear search and frequency counting.

Covers creating dictionaries, rules for keys, accessing values with [ ] and get(), adding, updating and deleting items, traversal, dictionary methods (keys, values, items, update, pop, popitem, setdefault, fromkeys, copy), nested dictionaries, list vs dictionary, and frequency-counting programs.

Covers what modules are, importing with import, as, and from-import, the math module (pi, e, sqrt, ceil, floor, pow, fabs, sin, cos, tan), the random module (random, randint, randrange) with possible-output questions, the statistics module (mean, median, mode), and creating your own module.

Covers digital footprints, netiquette, intellectual property rights and their violation, open source licences (GPL, Apache, Creative Commons), cyber crimes (hacking, phishing, ransomware, cyber bullying), cyber safety, malware, e-waste management, the IT Act 2000, and gender and disability issues in computing.