Compsci Unit 2

Primary Memory

Memory directly connected to the processor, volatile, used for immediate data access.

Secondary Memory

Long-term storage, non-volatile, used for storing data permanently.

Processor Speed

Speed at which the processor executes instructions, measured in MIPS (Millions of Instructions Per Second).

Bandwidth

Rate at which data travels between the processor and memory, expressed in Mb/s.

Screen Resolution

Number of distinct pixels displayed on a screen, given as width x height.

Graphics Processor (GPU)

Processor efficient at manipulating graphics and images, can be integrated or separate.

Sound Processor

Processor handling audio signals, mostly integrated but can be sold separately.

Mainframe

Computer designed for handling many input/output devices and bulk data processing.

Supercomputer

Computer designed for large or complex mathematical calculations.

Server

Device providing services, data, or resources to other computers on a network.

PC (Personal Computer)

Computer that can be bought or built to suit user needs and can be modified.

Tablet

Portable computer with a touchscreen interface, different from a laptop.

Laptop

Portable computer that can run the same OS as a PC.

Smartphone

Mobile device with computing capabilities, including various sensors.

Digital Camera

Device for taking pictures and videos, equipped with sensors for image quality.

Rendering

Process of generating an image or animation from a model.

Single-program Operation

System where only one program runs at a time.

Batch Processing

System executing a batch of tasks sequentially without user interaction.

Multiprogramming

Method where multiple programs are loaded into memory to increase CPU utilization.

Multitasking

Running multiple tasks simultaneously by rapidly switching between them.

Time Sharing

System allowing multiple users to interact with a computer simultaneously.

Time Slicing

Time allocated to each user in a multi-user or multitasking system.

Multiprocessing

Using multiple processors to execute tasks simultaneously.

Multithreading

Method where different parts of a program are executed simultaneously.

Multi-access

Allowing multiple users access to a system or resource at the same time.

Memory Leak

When a program does not release allocated memory, reducing available memory.

Address Binding

Process where the OS converts a logical address into a physical address.

Swapping / Paging

Moving data between RAM and secondary memory to manage limited RAM resources.

Virtual Memory

Memory management technique using secondary memory to extend available RAM.

Scheduling

Method used by the OS to manage the order of process execution.

Task Scheduler

Tool allowing the OS to create and manage tasks at specific times.

Interrupts

Signals from devices or programs that stop the current task for OS action.

Device Driver

Software enabling OS communication with hardware devices.

Polling

Method where the CPU checks device status periodically for attention.

Dedicated OS

OS designed for a specific type of device, like a mobile device.

Abstraction

Process of hiding complexity to focus on essential aspects.

Complexity Hiding (Examples)

Using device drivers to avoid OS needing hardware details.

Virtual memory

Hides physical addresses from the user and software while allowing the OS to allocate currently available memory space.

Java Virtual Machine

Allows programs coded in Java to run even if the hardware doesn't understand Java directly.

Operating System (OS)

Main functions include recognizing input from a keyboard, sending output to the display, ensuring applications do not interfere with each other, and providing a platform for application software.

Input devices

Device drivers hide the hardware complexity from users and other software.

Drive letters

Indicate the type of storage of a device and hide the complexity of the hardware from users.

Shortest Job First Scheduling

A scheduling algorithm where the shortest jobs are run before longer tasks.

Multilevel Queue Scheduling

A scheduling algorithm where tasks are sorted into priority queues, with higher priority tasks processed first.

Multi-user system

The OS ensures that all users are authorized to access the system and have specific permissions to perform tasks.