Computer Systems Study Guide

Flashcards covering key vocabulary and concepts from the Computer Systems study guide.

Memory Hierarchy

An arrangement of memory types that balances cost, speed, and storage capacity.

Memory Hierarchy Diagram

"Real Computers Make Fast Tasks Run."

Primary Storage

Volatile memory directly accessible by CPU, used for running applications and active data. (RAM)

Secondary Storage

Non-volatile, long-term data storage, such as HDDs or SSDs, used for file storage and backups.

Cache Memory

L1: Fastest, smallest, closest to CPU cores
L2: Larger, slightly slower than L1
L3: Largest, slowest cache, shared among cores.

Cache Memory: Direct Mapping

Each block of main memory maps to exactly one cache line

Cache Memory: Associative Mapping

Any block can go into any cache line. (Flexible but slower)

Cache Memory: Set-Associative Mapping

Combines direct and associative; memory blocks map into a set of lines

Operating Systems

Software managing hardware resources, providing services to software.

Functions: Resource management, memory management, task scheduling, I/O control, security

Multiprogramming

A method where several programs run simultaneously to maximize CPU usage.

Multithreading

Multiple threads running within a single program, similar to multiprogramming but within one application

OS Kernel

Core component managing system resources, memory, processes, and hardware interaction.

User Mode

A restricted mode where applications run with no direct access to hardware.

Kernel Mode

A mode with full access to hardware and memory, allowing OS code execution.

Processes

A running instance of a program. Needed to allocate resources, manage tasks

Processes Diagram

Interrupts

Hardware-generated signals that temporarily stop CPU tasks to handle important events.

Traps

Software-generated signals or errors requiring OS intervention.

Virtual Memory

A technique that provides the illusion of a large memory space to programs. Allows execution of processes larger than available physical memory.

Paging

The process of dividing memory into fixed-size blocks for easy management.

Paging Tables

Structures mapping virtual memory addresses to physical addresses

Memory Management Unit (MMU)

A component that translates virtual memory addresses to physical addresses.

Translation Lookaside Buffer (TLB)

Fast memory storing recent page translations, improving access speed.