CS | Topic 2 | Computer Organization

Accumulator Register (AC)

A type of register that temporarily stores data from arithmetic/logical operations/calculations performed by the ALU

1. It eliminates the need to store these results in the RAM(which is slower, as it takes a longer time to access)

2. Making the CPU more efficient

3. AC speeds up the process by avoiding unnecessary slow data transfers

Arithmetic Logic Unit (ALU)

Performs arithmetic and logical operations/calculations

eg, addition, subtraction, AND, OR, etc.

Binary

Uses two symbols, 0 and 1, BASE-2

Binary Digit (Bit)

The basic unit of information in a computer system consisting of 0 and 1s

Byte

Bits grouped together to form a byte

1 Byte = 8 Bits

CAD

type of application software

create, modify, and analyse a design

increase productivity

Database

type of application software

provides an interface between the user and the database, lets them organise sorted data

create/modify queries and extract data

Define Cache Memory

A small, high-speed volatile memory used to store the most frequently accessed instructions/data by the CPU

Since it's closer the the CPU, it is faster than the RAM

Reduces the need to access the RAM, which takes longer to access (slow), increasing performance speeds

First checks if there's a copy in Cache, if not, it checks the RAM

Define Central Processing Unit (CPU)

CPU is a component of a computer system that processes and executes instructions/data

Define Memory Data Register (MDR)

A type of Register that temporarily stores data/instructions fetched from OR to be written in memory, connected to the RAM through a Data Bus

Define Primary Memory

Storage for Data/Instructions actively used/accessible by the CPU

Define Random Access Memory (RAM)

Temporarily stores data/instructions for all actively running programs/processes

RAM is organized in memory locations with a unique address, constantly being written/updated/read

It is Volatile Memory, all instructions/data held are lost and deleted when the computer's power is off

Define Read Only Memory (ROM)

Stores permanent instructions/data required for the computer to boot and operate, including the BIOS

It is read only cannot be overwritten.

Non-Volatile, instructions/data are saved, even when computer's power is off

Smaller than RAM

Define Virtual Memory

Uses the secondary memory (computer's HDD), mimicking the primary memory

When the RAM is full, unnecessary programs that aren't in use are swapped into the secondary memory to free up space, and if demanded again, will be swapped out and into the RAM.

Define the Control Unit (CU) and its Characteristics

The Control Unit deals with loading (fetches data/instructions from memory) and decoding instructions

1. It manages the execution of instructions/data by controlling the operations of the CPU

2. It controls the flow of data between the CPU, RAM, and Input/Output Devices, understanding where the data needs to go

3. Ensures synchronization with the system clock, ensuring all operations are performed in the right sequence and time

Define the Memory Address Register (MAR)

MAR is a register that temporarily stores the memory address for the next instructions/data to be accessed by the CPU, sent the the RAM through an Address Bus.

MAR tells where to look for in the RAM

Define the Secondary Memory

Utilizes the computer's HDD

Slower than RAM, but has a Larger Capacity

Persistent Storage, data/instructions remain even when power is off

Necessary data/instructions are copied over to the RAM when demanded

Since RAM has a Limited Capacity, data/instructions that aren't needed/demanded are moved to the secondary memory to free up space

Define Denary

A number system with 10 symbols, BASE-10

Email

type of application software

Exchange of digital messages on an email server

Recipients receive messages by connecting to the email server

Explain the Machine Instruction Cycle (Step By Step)

Machine Instruction Cycle is the basic operational process of how the CPU processes instructions

1. Program Counter (PC) holds the next address to be executed

2. PC passes the address to the MAR through an address bus

3. CPU takes the address temporarily stored in the MAR, and uses it to fetch instructions/data in memory, which is then passed and stored into the MDR

4. MDR passes the instructions/data fetched from RAM to the Instruction Register (IR), IR holds instructions/data currently being processed. The CU decodes instructions in the IR

5. Decoded instruction is then passed to the ALU for execution, and results are stored in the AC.

6. The results are then passed to the MDR, if it needs to be written in memory.

Graphic Processing

type of application software

Manipulation of images, cropping, cutting, etc.

Define Hexadecimal

A numbering system with 16 symbols, BASE-16, used to represent very large numbers like color

0-9 numbers

10-15 represents A-F

Memory Management

function of an operating system

Memory management controls which application has access to which area in memory, and allocates a section of memory to applications, keeping track of where data is.

eg. file management

Peripheral Management

function of an operating system

Operating System controls hardware (printer, keyboard, USB, etc) through device drivers, while allowing applications to use them without directly managing/accessing hardware

aka the OS acts as an intermediary between hardware and software

Registers

Very small, fast circuits that temporarily store calculations/operations inside the CPU

Since it is inside the CPU, it is the fastest type of memory (faster than RAM)

Thus, it speeds up processing, holding instructions/data actively needed and used by the CPU

Resource Allocation

function of an operating system

Allocates a slice of CPU time for each application depending on their priority

slower applications = more time

faster applications = less time

Security

function of an operating system

provides security measures such as password authentication, preventing unauthorized access

Spreadsheets

type of application software

Data organised in rows and columns

perform calculations to process data,

create visual charts for analysis

Web Browser

type of application software

Access content on the World Wide Web

Retrieves the content request by the user by requesting the web server

present content received which user requested

What is a Data Bus

Data Bus is Bidirectional (can flow in two directions),

It is a physical connection transfer data/instructions from and to the CPU

What is an Address Bus

Address Bus is Unidirectional (only flows towards one direction)

It is a physical connection that transfers the memory address for instructions/data to where it wants to read/write

Word Processing

type of application software

Production of Documents

Features like formatting, editing, and printing