Computer Systems Fundamentals Flashcards
(34 cards)
What is a server and what is the purpose of a server.
A server is a powerful, reliable computer that provides services, data, and resources to client devices over a network. They are built for: High availability, reliability, efficiency, often 24/7 operation.
Types of servers
Web Servers: Host websites (e.g., Apache, Nginx).
File Servers: Store/manage network files.
Mail Servers: Manage email (e.g., Microsoft Exchange, Postfix).
Application Servers: Run business applications.
What is a mainframe and what are their uses
A mainframe is a powerful, large-scale computer system built to process massive data volumes and support thousands of users simultaneously. They are commonly used in Banking, government records, healthcare, retail logistics.
What is an embedded system and their applications
An embedded system is a specialised computer system built to perform a specific task within a larger machine. They are used in consumer electronics, automotive, medical devices, home appliances.
What are the key features of a mainframe
High Processing Power: Millions of transactions per second.
Massive Storage: Handles vast structured/unstructured data.
Reliability: 24/7 operation with fault tolerance.
Security: Advanced encryption and data protection.
What are the features of an embedded system
Compact and Cost-Effective
Highly Reliable
Low Power Consumption
What is distributed system and what are their applications
A distributed system is a network of computers working together to complete tasks by sharing resources. Social media, e-commerce, online banking, Blockchain and cryptocurrencies.
What are the types of distributed system
Client-Server (e.g., web apps, email).
Cloud Computing (e.g., AWS, Google Cloud).
Grid Computing (e.g., climate modelling).
Peer-to-Peer (e.g., BitTorrent, blockchain).
Explain multi user system
A multi-user system allows multiple users to access a computer system simultaneously. It’s features include:
1. Time sharing
2. Resource sharing
3. User isolation: Each user has separate login credentials
Examples of multi-user system are:
1. Cloud Computing
2. Database servers
3. Mainframes
Explain multi tasking systems
A CPU handles multiple tasks at once.
Features: Context switching, process scheduling, efficient CPU use.
Types:
Pre-emptive (OS controls task switching — Windows, Linux).
Cooperative (Tasks yield control — older Mac OS).
Examples: Browsing while downloading, using multiple apps at once.
Explain Network system
A network system consists of multiple computers connected together to share resources and communicate. It’s features are:
1. Decentralised or centralised management: Servers control resources, while clients access them.
2. Data and resource sharing: Users can share files, printers, and applications over the network.
3. Security mechanism
Types of Network Systems are: Client-Server, Peer-to-Peer, Cloud Networks.
Examples: Internet, corporate intranets, cloud storage.
Explain what polling is
Polling is a method where the CPU repeatedly checks an I/O device’s status to see if it needs service. Advantages are:
1. Simple to implement.
2. Predictable timing.
3. Effective for fast devices.
Disadvantages are:
1. Inefficient CPU usage (wastes cycles).
2. Delayed response if multiple devices are polled.
3.Poor scalability with many devices.
Explain interrupts
Interrupts allow I/O devices to signal the CPU only when attention is needed, making it more efficient than polling. Advantages:
1. Efficient CPU usage (no constant checking).
2. Faster response time to events.
Disadvantages are:
1. More complex implementation (interrupt handlers).
2. Interrupt overhead
3. Requires priority handling to avoid conflicts
How does polling work?
- The CPU checks the status register of an I/O device to see if it is ready
- If the device is not ready, the CPU continues checking at regular intervals (looping).
- If the device is ready, the CPU processes the request
How does interrupts work?
I/O device sends an interrupt request (IRQ).
CPU pauses, saves state, executes Interrupt Service Routine (ISR), then resumes previous task.
What is I/O operations
I/O operations manage the data transfer between the CPU and peripheral devices. Different types—Programmed I/O, Interrupt-Driven I/O, and Direct Memory Access (DMA)
What are the types of I/O operations
Programmed I/O (PIO)
Interrupt-Driven I/O
Direct Memory Access (DMA)
Explain Programmed I/O
CPU actively manages I/O and waits for completion. It uses polling to repeatedly check if the device is ready.
Pros: It is simple to use
Cons: Inefficient, The CPU is occupied.
(See comparisons)
Explain Interrupt-Driven I/O
Here the device interrupts the CPU when its ready.
Pros: More efficient; CPU can multitask.
Cons: Harder to manage multiple devices.
(See comparisons)
Explain Direct Memory Access
A DMA controller handles transfers without CPU.
Example: Copying a large file from a hard drive to RAM without CPU intervention.
Pros: Most efficient; ideal for high-speed transfers.
Cons: Complex; needs extra hardware.
(See comparisons)
What are device drivers
Device drivers are software that lets the operating system control hardware by translating its commands.
Importance:
Improve security and system stability through updates.
Optimize performance (e.g., GPU drivers).
Ensure hardware compatibility with the OS.
Usage:
Daily use: mouse, keyboard, printers.
Gaming: graphics and audio drivers.
Business
What is RAM
Random Access Memory. It is the read write memory or primary or main memory. It stores data and programmes used by tHe CPU. It is also volatile meaning data is lost when power is off. It is divided into SRAM and DRAM
What is DRAM
Known as dynamic RAM, It is used as main memory and it stores data in capacitors that must be refreshed every few millisecond. It’s slower and cheaper.
What is SRAM
Known as Static RAM, It is used as cache and it stores data using transistors. It doesn’t need to be refreshed. It is faster but more expensive.
