Operating System Tutorial

Operating System Tutorial Types of Operating System Evolution of Operating System Functions of Operating System Operating System Properties Operating System Services Components of Operating System Needs of the Operating System

Operating Systems

Linux Operating System Unix Operating System Ubuntu Operating System Chrome Operating Systems Fedora Operating System MAC Operating System MS Windows Operating System Solaris Operating System Cooperative Operating System CorelDRAW Operating System CentOS FreeBSD Operating Systems Batch Operating System MS-DOS Operating System Commercial Mobile Operating Systems


Difference Between Multi-programming and Multitasking Difference between C-LOOK and C-SCAN Difference between Rotational Latency and Disk Assess Time Trap vs Interrupt Difference between C-SCAN and SSTF Difference between SCAN and FCFS Difference between Seek Time and Disk Access Time Difference between SSTF and LOOK Difference between Process and Program in the Operating System Difference between Protection and Security in Operating System

How To

How to implement Monitors using Semaphores How to Install a Different Operating System on a PC


What is Kernel and Types of Kernel What is DOS Operating System What is Thread and Types of Thread What is Process Scheduler and Process Queue What is Context Switching What is CPU Scheduling What is Producer-Consumer Problem What is Semaphore in Operating System Monitors in Operating System What is Deadlock What is Paging and Segmentation What is Demand Paging What is Virtual Memory What is a Long term Scheduler What is Page Replacement in Operating System What is BSR Mode What is Convoy Effect What is Job Sequencing in Operating System Why is it critical for the Scheduler to distinguish between I/O-bound and CPU-bound programs Why is there a Need for an Operating System


Process Management Process State Scheduling Algorithm FCFS (First-come-First-Serve) Scheduling SJF (Shortest Job First) Scheduling Round-Robin CPU Scheduling Priority Based Scheduling HRRN (Highest Response Ratio Next) Scheduling Process Synchronization Lock Variable Mechanism TSL Mechanism Turn Variable Mechanism Interested Variable Mechanism Deadlock Avoidance Strategies for Handling Deadlock Deadlock Prevention Deadlock Detection and Recovery Resource Allocation Graph Banker’s Algorithm in Operating System Fixed Partitioning and Dynamic Partitioning Partitioning Algorithms Disk Scheduling Algorithms FCFS and SSTF Disk Scheduling Algorithm SCAN and C-SCAN Disk Scheduling Algorithm Look and C-Look Disk Scheduling Algorithm File in Operating System File Access Methods in Operating System File Allocation Method Directory Structure in Operating System N-Step-SCAN Disk Scheduling Feedback Queue in Operating System Contiguous Memory Allocation in Operating System Real-time Operating System Starvation in Operating System Thrashing in Operating System 5 Goals of Operating System Advantages of Operating System Advantages of UNIX Operating System Bit Vector in Operating System Booting Process in Operating System Can a Computer Run Without the Operating System Dining Philosophers Problem in Operating System Free Space Management in Operating System Inter Process Communication in Operating System Swapping in Operating System Memory Management in Operating System Multiprogramming Operating System Multitasking Operating Systems Multi-user Operating Systems Non-Contiguous Memory Allocation in Operating System Page Table in Operating System Process Scheduling in Operating System Segmentation in Operating System Simple Structure in Operating System Single-User Operating System Two Phase Locking Protocol Advantages and Disadvantages of Operating System Arithmetic operations in binary number system Assemblers in the operating system Bakery Algorithm in Operating System Benefits of Ubuntu Operating System CPU Scheduling Criteria in Operating System Critical Section in Operating System Device Management in Operating System Linux Scheduler in Operating System Long Term Scheduler in Operating System Mutex in Operating System Operating System Failure Peterson's Solution in Operating System Privileged and Non-Privileged Instructions in Operating System Swapping in Operating System Types of Operating System Zombie and Orphan Process in Operating System 62-bit operating system Advantages and Disadvantages of Batch Operating System Boot Block and Bad Block in Operating System Contiguous and Non - Contiguous Memory Allocation in Operating System Control and Distribution Systems in Operations Management Control Program in Operating System Convergent Technologies in Operating System Convoy Effect in Operating System Copy Operating Systems to SSD Core Components of Operating System Core of UNIX Operating System Correct Value to return to the Operating System Corrupted Operating System Cos is Smart Card Operating System Cosmos Operating Systems Examples Generation of Operating System Hardware Solution in Operating System Process Control Block in Operating System Function of Kernel in Operating System Operating System Layers History of Debian Operating Systems Branches and Architecture of Debian Operating Systems Features and Packages of Debian Operating Systems Installation of Operating System on a New PC Organizational Structure and Development in Debian Operating Systems User Interface in Operating System Types Of Memory in OS Operating System in Nokia Multilevel Paging in OS Memory Mapping Techniques in OS Memory Layout of a Process in Operating System Hardware Protection in Operating System Functions of File Management in Operating System Core of Linux Operating System Cache Replacement Policy in Operating System Cache Line and Cache Size in Operating System What is Memory Mapping? Difference Between Network Operating System And Distributed Operating System What is the difference between a Hard link and a Soft Link? Principles of Preemptive Scheduling Process Scheduling Algorithms What is NOS? What is the Interrupt I/O Process? What is Time Sharing OS What is process termination? What is Time-Sharing Operating System What is Batch File File system manipulation What is Message-passing Technique in OS Logical Clock in Distributed System

Types Of Memory in OS

To know about the types of memory, we must know about the difference between the term storage and memory first. Storage is known as the secondary memory; in this, the data of a computer is kept; some of the examples of storage are devices such as Hard disk drives, Solid state drives, etc. Storage is not that easy to be lost. It is non-volatile. Even when the system is turned off and on, the storage is kept as it is without altering the actual data, which can be important to the user. Some examples of storage devices are Compact disks (CD), Digital versatile discs (DVD), and Blu-ray disks.

The term memory means the primary storage of the computer. Random access memory (RAM) is one example of memory. The memory will process the information. The data is only stored temporarily for a short period of time. Unlike storage, where it is permanent until we delete it, memory is volatile, meaning it is stored for a short period of time for faster access to perform the actions quickly. If the system is turned off, then the data from the memory is lost. The memory only works when there is a running program; the data from the program is stored for some time to access it quicker. Some examples of memory are RAM, Read-only memory (ROM), and magnetic strips.

The capacity of these devices will be different. As we discussed that storage is used to store the data in the computer system for a long period of time, files such as important documents, documents, images, etc. The memory stores the data only for a shorter period of time, so it requires only less capacity of space. So, the memory devices only range from 2GB to 64GB, which is its maximum space; this depends on the specifications. The storage devices can range up to 16GB to 1TB; they can also exceed 1 Tera byte. The storage devices have a massive amount of space because it is used to store the necessary documents in them without any loss. But the memory is only for a temporary time. So, memory devices have less space compared to storage devices.

Types of memory

Memory devices are classified into two types

  1. Primary memory
  2. Secondary memory
Types Of Memory in OS

Let us understand each of the classifications in detail.

Primary memory

Primary memory is the type of memory where the CPU can access the memory directly. This provides faster access time, and this is faster than the speed provided by the cache memory. This type of memory is volatile.

1. Random access memory (RAM)

RAM is a type of memory used in computers that is faster to access by the CPU and is quicker in producing the outcomes. This is best suited for the read-and-write operation by the CPU. This helps in faster manipulation and access of the data that is stored temporarily. There are two types of Random access memory (RAM).

  1. Dynamic RAM (DRAM): This is a type of memory that is constructed by the semiconductors that are used by the program, which is necessary for the computer to complete its function. This is the most widely used type of RAM; this has faster refresh rates.
  2. Static RAM (SRAM): This is another type of RAM that is way faster than the DRAM; it uses flip-flops to store the data. This helps in removing the need to refresh the data repeatedly. This is used in cache memory due to less refreshing and more lifetime than in DRAM.
  3. There are other types of RAM, namely, DDR SDRAM (Double Data Rate Synchronous DRAM). This is an improved and enhanced version of DRAM, which is used to transfer data at faster speeds than DRAM. Another type is DDR 4 SDRAM which is another type of DRAM which provides high bandwidths for the transfer of data for reading and writing the data.

2. Read-only memory (ROM)

This is a type of memory device used in computers; this is a non-volatile type of memory device. This is only used to read the data; no writing operations are done to it. ROM contains the data that is used to power up the computer with its basic needs.

There are 3 types of ROM:

  1. Programmable ROM (PROM): This is one of the types of ROM that provides additional features to it. Users can program a small amount of code into it of their choice. The programming is done by using a programmer designed for programming PROM
  2. Erasable ROM (EROM): This type of PROM is made so that the programmed code can be erased and then reused again in future. The erasing process is done in a typical way where a UV light is shined onto the chip.
  3. Electrically erasable ROM (EEROM): This is also another type of ROM that can be erased and programmed, unlike EROM, where a small amount of electric current is passed to erase the program.

Secondary Memory

This is a type of memory that is not integrated into the CPU; this is an external type of memory. This is used for longer storage of the data for a computer device.

1. Magnetic memory

In this type, the memory is stored in a magnetic material to store the data.

  1. Floppy disks: These are a type of magnetic memory which is used to store data in circles. These provide very less amount of storage.

2. Optical memory

These types of secondary memory provide larger storage than floppy disks; these are made of a polycarbonate material which is coated with a reflective material.

Compact disks and DVDs are the most common examples; CDs provide about 700MB of storage which can store audio, video, etc.