IB CS Topic 2 - Computer Architecture

Central Processing Unit (CPU)

executes commands from a computer's hardware and software; the principal computer chip that contains several processing components, which determines the computer's operating speed; the "brain" of a computer

Program Counter

The register that contains the address of the next instruction to be executed

Memory Address Register (MAR)

Holds memory address for data or a instruction about to be used by the CPU

Random Access Memory (RAM)

Computer location where instructions and data are stored on a temporary basis. This memory is volatile.

Volatile memory

Storage that is wiped clean when power is cut off from a device

non-persistent storage

A form of storage that does not maintain its data through power loss.

Memory Data Register (MDR)

a register that contains the data value being fetched or stored from RAM

Control Unit (CU)

Processor component that manages the execution of instructions during the fetch

Arithmetic Logic Unit (ALU)

The part of the central processing unit that performs arithmetic computations and logical operations. Receives data from the Control Unit

Accumulator (ACC)

Stores the results of any arithmetic or logical operations carried out by the ALU.

Current Instruction Register (CIR)

Register that stores the instructions that the CPU is currently decoding/executing

Read Only Memory

the portion of a computer's primary storage that does not lose its contents when one switches off the power. Holds fundamental instructions on a computer like the BIOS Setup.

Cache Memory

A type of memory used to temporarily store frequently used data or programs for quick access; similar to RAM but faster.

Hard Drive

an internal or external computer component that stores data, such as the operating system, applications, and user files. HDDs are "non-volatile" storage devices, meaning they retain stored data even when power isn't being supplied.

Virtual Memory

Space on a hard disk or other storage device that simulates random access memory. When primary memory gets overloaded, data gets sent here and stored in "pages". It gets returned to primary when it is needed.

Operating System

Set of software that controls computer's hardware and resources and provides services for computer programs.

User Interface

The visual elements of an program through which a user controls or communications the application. Often abbreviated UI. Link between user and hardware.

Memory Management

Operating system activity that optimizes the use of random access memory (RAM).

Peripheral Management

Software responsible for handling input, output and storage devices. Coordinates between BIOS and device drivers to manage interactions between computer and peripherals.

Multitasking

supports running multiple applications seemingly simultaneously. Allocates CPU Cycles to concurrent programs based on priority and time.

Application Software

computer software created to allow the user to perform a specific job or task

ASCII

a code for representing English characters as numbers, with each letter assigned a number from 0 to 127

Hexadecimal

A base-16 number system that uses sixteen distinct symbols 0-9 and A-F to represent numbers from 0 to 15.

Binary

The binary number system is base 2, using only bits 0 and 1.