COMPX101 Written Test 1 Flashcards

23rd of April test

💻 COMPUTER BASICS

Motherboard

Houses key components (CPU, RAM, storage) and provides input/output ports and power connections.

Input Devices

Devices used to enter data (keyboard, mouse, scanner, microphone, camera).

Output Devices

Devices that display or output results (monitor, printer, speaker, projector, headphones).

🧠 MEMORY & STORAGE

Computer Memory

Physical devices that store data, instructions, and results (temporary or permanent).

Main Memory

Memory where programs and data are loaded before being processed by the CPU.

RAM (Random Access Memory)

Volatile memory; temporary storage that loses data when power is off.

ROM (Read Only Memory)

Non-volatile memory; permanent storage that cannot be modified easily.

Serial Access

Data cannot be accessed directly; must go through sequence.

Memory Cell

Stores a single bit (0 or 1).

Memory Address

Unique binary identifier for each memory location.

Byte Addressable Memory

Each byte has its own unique address.

Bus

System that transfers data between computer components.

⚙️ CPU (CENTRAL PROCESSING UNIT)

CPU

Component of a computer that executes instructions and processes data.

Control Unit (CU)

Controls and coordinates CPU operations.

Arithmetic Logic Unit (ALU)

Performs calculations and logical operations.

Registers

Small, fast storage inside CPU for temporary data.

Word Size

Amount of data CPU can process at once (e.g., 32-bit, 64-bit).

🧾 REGISTERS

Memory Address Register (MAR)

Stores address of memory location to access.

Memory Data Register (MDR)

Stores data being read/written.

Program Counter (PC)

Stores address of next instruction.

Instruction Register (IR)

Holds current instruction being executed.

General Purpose Registers

Temporary storage for calculations.

🔁 INSTRUCTION CYCLE

Instruction Cycle

Fetch → Decode → Execute process.

Fetch

Get instruction from memory.

Decode

Interpret instruction.

Execute

Perform the instruction.

🧮 VARIABLES & DATA TYPES (C#)

Variable

Storage location for data.

Declaration

Type Name = Value;

int

Whole numbers.

double

Decimal numbers with high precision.

char

Single character.

bool

True or false.

string

Sequence of characters (text).

🔄 TYPE CONVERSION

Conversion

Changing data from one type to another using Convert class.

Parse

Converts string → numeric types (int, double).

Concatenation

Combining values using “+”.

🎯 CASTING

Implicit Casting

Automatic, no data loss (int → double).

Explicit Casting

Manual, possible data loss (double → int).

⚠️ EXCEPTIONS

Exception

Error during program execution.

Try-Catch

Method in programming that handles errors safely (try = test, catch = handle error).

🔀 CONTROL STRUCTURES

Sequence

Statements executed in order.

Selection

Decision-making (if/else).

Iteration

Repeating code (loops).

🔁 LOOPS

For Loop

Runs fixed number of times.

While Loop

Runs while condition is true.

Do-While Loop

Runs at least once before checking condition. Executes the code in it before it checks the condition.

Counter-Controlled Loop

Runs specific number of times (while loop with a counter or the for loop).

Sentinel-Controlled Loop

Runs until condition is met (while loop that runs while it is true)

Increment (i++)

Increases loop variable.

🎲 RANDOM NUMBERS

Random Numbers

Numbers with no predictable pattern.

True Random Numbers

Generated from physical processes (slow, unpredictable).

Pseudo-Random Numbers

Generated using algorithms, mostly using the time (fast, predictable with seed).

Seed

Starting value for pseudo-random generation.

🐞 DEBUGGING

Debugging

Finding and fixing errors in code.

Breakpoint

Pauses execution at a line.

Step Into

Goes inside methods.

Step Over

Skips method details.

Step Out

Exits current method.

🛠️ COMPILERS & CODE

Compiler

Converts high-level code to machine code.

Machine Code

Binary instructions executed by CPU.

Assembler

Converts assembly language to machine code.

Source Code

Human-readable program code.

🖥️ OPERATING SYSTEM

Operating System (OS)

Software that manages hardware and software resources.

OS Functions

Controls programs, manages memory, provides user interface.

Examples

Windows, Linux, macOS, Android, iOS.

🔄 PROGRAM EXECUTION FLOW

Program Execution

OS loads program → program runs → control returns to OS.

🧪 WRAMP INSTRUCTION CYCLE

WRAMP Cycle

1. Fetch instruction

2. Decode instruction

3. Increment Program Counter (PC)

4. Execute instruction

EXTRA CODING CONCEPTS

Modulus (%)

Finds remainder (used for even/odd checks).

"\n"

New line in output.