Computer architecture

what does the CPU do

it performs the machine instruction system cycle to handle all the arithmetic, logical and I/O operations. It receives data to process and store

What is the ALU

The ALU is a fundamental component of the CPU responsible for performing all arithmetic and logical operations.It executes basic arithmetic operations such as addition, subtraction, multiplication, and division, and logical operations like AND, OR, NOT, and XOR.

What is the CU

operates the CPU by telling the ALU, Memory, and I/O devices how to respond to the instructions received from the computer’s memory. It decodes the instruction, and then coordinates and manages the data flow in and out of the CPU, the ALU, and the memory.

what is a register

A register is a small, extremely fast storage location inside the CPU used to temporarily hold data, instructions, or addresses during processing.

What is the MAR

MAR (is a register in the CPU that) stores the address of the (next) instruction/data;
to be read from/written to RAM;

What is the Memory Data Register (MDR)

Temporarily holds the data that is being transferred to or from the memory. Acts as a buffer between the CPU and the main memory.

what is the Program Counter (PC)

Holds the address of the next instruction to be executed, automatically incrementing to sequence through the program correctly.

What is the Accumulator (ACC)

A special-purpose register that stores the results produced by the ALU. It's a critical component in processing data and instructions.

what is the Instruction Register/CIR Current Instruction Register  (IRor CIR)

Contains the instruction currently being executed. Instructions are broken down into parts to be deciphered and acted upon. 

what is the IR Index Register

The IR is used to store the value of the current index being accessed. Used when accessing array variable, by indexing the address to be accessed a loop can be used to iterate the value of the index to be accessed. This is illustrated in the assembly language section.

how does the cpu and input/output interact with eachother

I/O devices like keyboards, mice, and printers communicate with the CPU, either sending data to be processed or receiving data from the CPU.The CU manages and controls the exchange of data between the I/O devices and the CPU, coordinating how data is received and sent.

the interaction between the CPU and storage

Directly accessible by the CPU, primary storage (like RAM and ROM) temporarily holds data and instructions.Involves longer-term data storage devices like hard drives and SSDs. Data from these devices is loaded into primary storage when needed for processing.

what is the data bus

 Data bus is a physical connection to transport data from-to CPU to be processed;

what is the address bus

Physical connection that transports memory addresses from the CPU to other components such as RAM

What is the Primary Storage

 type of computer memory that is directly accessible by the CPU (Central Processing Unit). It is used to temporarily store data and instructions that the CPU is currently working on. Primary storage typically includes Random Access Memory (RAM) and read-only memory (ROM), which is non-volatile and The size and speed of primary storage can have a significant impact on the performance of a computer system.

What is ROM

non-volatile memory that is used to store firmware or software that is permanently programmed into the computer. Data stored in ROM cannot be modified, or can only be modified with great difficulty, and remains even when the power is turned off. It is typically used to hold essential boot-up instructions or system software.

What are the types of ROM

Masked ROM (MROM): The data is permanently written during the manufacturing process. It cannot be altered afterward, making it the least flexible type of ROM.

Programmable ROM (PROM) - can be written once

Erasable Programmable ROM (EPROM) - erased with UV light and programmed

Electrically Erasable Programmable ROM (EEPROM) - can be erased electrically. Removed one byte at a time which is time consuming

What is the RAM

RAM (Random Access Memory) is a volatile main memory used to store data and instructions that are currently being accessed by the CPU. RAM is volatile memory, meaning that its contents are lost when the computer is turned off or restarted.

What are the types of RAM

Dynamic RAM(DRAM) - needs regular refreshing of data. This is common and cheap but slower

Static RAM (SRAM) - It is faster and more expensive, thus and used less due to its cost. A small amount of SRAM is placed between the main RAM and the processor called cache.

What is the Cache Memory

Cache memory is a small, high-speed memory located within or very close to the CPU. It stores frequently accessed data and instructions so that they can be retrieved more quickly than from main memory (RAM). This reduces the time the CPU spends waiting for data, thereby improving system performance. Cache acts as a buffer between the CPU and RAM, helping to overcome the speed difference between them. When the CPU needs to read from the primary memory, it first checks if a copy of the data exists in the cache, this is a way to speed up the process.

What are the types of the Cache memory

• Levels of Cache: Modern CPUs feature multi-level cache architectures (L1, L2, and sometimes L3) to optimise performance.

  • L1 cache is smallest in size but offers the highest speed. It's typically integrated directly within the CPU chip.

  • L2 cache, larger than L1, is either incorporated into the CPU or situated very close to it.

  • L3 cache, common in multi-core processors, is shared among the cores and is slower but larger than L1 and L2.

What is the Secondary Storage

Secondary storage used to store data and programs that are not currently being used or accessed by the computer's CPU (Central Processing Unit) and is used to store data for long term. Unlike primary storage, which provides fast access to frequently used data, secondary storage devices typically have slower access speeds but offer much larger storage capacity. This makes them ideal for storing large files such as videos, photos, and documents, as well as backups of important data.

Examples of the secondary storage devices

1. Hard disk drives (HDD)

2. Solid-state drives (SSD)

3. Optical discs (CD, DVD, Blu-ray)

4. USB flash drives

5. Memory cards (SD, microSD)

6. Magnetic tapes

7. External hard drives

8. Network-attached storage (NAS) devices

9. Cloud storage services.

Define the term Bit

the basic unit of measure in a computer system with only two values. 0 and 1

What are operating systems

Software that manages the hardware and software resources of a computer it acts as a intermediary between the computer hardware and the application that run on the computer. The operating system provides the necessary support and services to run applications, manage memory, handle input/output operations, and perform other tasks. It is the first software that is loaded when the computer starts up, and it runs continuously in the background, providing the necessary resources and services to other programs. Examples of popular operating systems include Windows, macOS, Linux, and Android. The basic functions of an operating system include:

What are the functions of the Operating System

1. peripheral communication

2. memory management

3. resource monitoring

4. Multitasking

5. Networking

6. data management

7. Security

What is the application software

Application software, also known as an app or application, is a type of computer software designed to perform specific tasks or functions for the user. Unlike system software, which manages and operates the computer system, application software is used directly by the user to accomplish a particular task, such as creating a document, managing data, or browsing the internet.​ Application software, a critical component of computer systems, aids users in performing an array of tasks, each tailored to specific requirements. This segment delves into several types of application software: word processors, spreadsheets, database management systems, email, web browsers, computer-aided design (CAD), and graphic processing software, highlighting their uses and impact.

What are word processors

Word processors are fundamental tools for text manipulation and document creation. Their primary function is to facilitate the creation, editing, formatting, and printing of textual content.

• Functionality: Besides basic text editing, word processors offer features such as spell check, grammar review, text styling, and layout management. Advanced functions include track changes, comments, and mail merge.

• Examples: Microsoft Word, Google Docs, and Apache OpenOffice Writer.

• Usage in Different Fields: Extensively used in education for essay writing, in businesses for creating reports and documentation, and in publishing for composing books and articles.

what are spreadsheets

Spreadsheets are versatile tools for numerical data manipulation and analysis. They represent information in rows and columns, enabling data organization, storage, and complex calculations.

• Capabilities: Key functionalities include formula application, macro scripting, pivot tables for data summarisation, and graphical data representation such as charts and histograms.

• Key Software: Microsoft Excel, Google Sheets, and LibreOffice Calc.

• Application: Used for financial forecasting, budgeting, statistical analysis, and inventory management.

what are Database Management Systems (DBMS)

DBMSs are complex software systems used for efficient data management. They support the creation, retrieval, updating, and management of databases and are crucial in handling large volumes of data systematically.

• Primary Uses: Store and manage data securely, support data query and retrieval, and enable data manipulation. They also facilitate the administration of user access and data security.

• Popular DBMS Tools: Oracle, Microsoft SQL Server, MySQL, and PostgreSQL.

• Relevance: DBMSs find applications in various domains, including e-commerce, data analytics, and customer relationship management (CRM).

What are emails

Email software revolutionised personal and professional communication. It's used for sending and receiving digital messages, documents, and other media over the internet.

• Core Features: Beyond sending and receiving messages, email software provides features like contact management, spam filtering, and integration with other applications like calendars.

• Widely Used Platforms: Microsoft Outlook, Gmail, and Apple Mail.

• Significance: Indispensable in business for communication, coordination, and documentation.

What are web browsers

Web browsers serve as the gateway to the internet, enabling users to access, retrieve, and display content from the World Wide Web.

• Functionality: Browsers render HTML and other web languages to display web pages. Features include tabbed browsing, bookmarks, privacy modes, and synchronisation across devices.

• Common Browsers: Google Chrome, Mozilla Firefox, Safari, and Microsoft Edge.

• Utility: Critical for accessing information, e-commerce, online banking, and various other online services.

what are Computer-Aided Design (CAD)

CAD software is utilised predominantly in professional design and engineering contexts. It enables the creation of detailed 2D or 3D models, technical documentation, and assists in the design process.

• Applications: Used for architectural planning, engineering design, and creating animated films in the entertainment industry.

• Key Products: AutoCAD, SolidWorks, and SketchUp.

• Industry Importance: Essential in precision engineering, architectural design, and product development.

What are graphic processing software

Graphic software focuses on image creation, editing, and enhancement. It's essential in digital arts, web development, and image processing.

• Functionality: Core functions include photo editing, vector graphics creation, and layout design. Advanced features cover raster graphics editing, typography, and 3D modelling.

• Examples: Adobe Photoshop, Adobe Illustrator, and GIMP.

• Usage: Widely used in media and advertising industries, web design, and professional photography.