Mobile Computing deals with human computer interaction using mobile devices. It contains mobile hardware and software as well as mobile computing devices. A mobile computing infrastructure usually uses ad-hoc networks and communication protocols. This is considerably different than a traditional computing structure as it uses fixed topology and protocols.An image describing mobile computing architecture is as follows −As seen above, the mobile computing architecture contains various mobile devices such as mobile phones, mobile tablets, laptops etc. These devices are connected to the mobile network which is a part of the internet. All the data is linked to cloud computing data ... Read More

Disks are the mainly used mass storage devices. They provide the bulk of secondary storage in operating systems today.Disk StructureEach modern disk contains concentric tracks and each track is divided into multiple sectors. The disks are usually arranged as a one dimensional array of blocks, where blocks are the smallest storage unit.Blocks can also be called as sectors. For each surface of the disk, there is a read/write desk available. The same tracks on all the surfaces is known as a cylinder.Disk SchedulingThere are many disk scheduling algorithms that provide the total head movement for various requests to the disk. ... Read More

Storage management plays an important part in operating system. It deals with the storage procedures in the computer system using an operating system. Details about this is as follows −Memory ManagementMemory management plays an important part in operating system. It deals with memory and the moving of processes from disk to primary memory for execution and back again.The most important concepts in memory management are paging and segmentation. Details about these topics are given below −PagingIn a computer system, virtual memory can be created that is more than the actual memory available i.e. physical memory. To implement this, the concept ... Read More

Files are used to provide a uniform view of data storage by the operating system. All the files are mapped onto physical devices that are usually non volatile so data is safe in the case of system failure.File AttributesThe attributes of a file may vary a little on different operating systems. However, the common file attributes are −NameThis denotes the symbolic name of the file. The file name is the only attribute that is readable by humans easily.IdentifierThis denotes the file name for the system. It is usually a number and uniquely identifies a file in the file system.TypeIf there ... Read More

Open Source operating systems are released under a license where the copyright holder allows others to study, change as well as distribute the software to other people. This can be done for any reason. The different open source operating system available in the market are −CosmosThis is an open source operating system written mostly in programming language C#. Its full form is C# Open Source Managed Operating System. Till 2016, Cosmos did not intend to be a fully fledged operating system but a system that allowed other developers to easily build their own operating systems. It also hid the inner ... Read More

Real time systems are those systems that work within strict time constraints and provide a worst case time estimate for critical situations. Embedded systems provide a specific function in a much larger system. When there is an embedded component in a real time system, it is known as a real time embedded system.Types of Real Time Embedded SystemsThere are primarily two types of real time embedded systems i.e. hard and soft. An illustration to explain this further is −Hard Real Time Embedded SystemThis type of system makes sure that all critical processes are completed within the given time frame. This ... Read More

There are two modes of operation in the operating system to make sure it works correctly. These are user mode and kernel mode.A diagram that illustrates the transition from user mode to kernel mode and back again is as follows −The following are the modes −User Mode:The system is in user mode when the operating system is running a user application such as handling a text editor. The transition from user mode to kernel mode occurs when the application requests the help of operating system or an interrupt or a system call occurs.The mode bit is set to 1 in ... Read More

Supervisor mode or privileged mode is a computer system mode in which all instructions such as privileged instructions can be performed by the processor. Some of these privileged instructions are interrupt instructions, input output management etcThe privilege levels of different components in a system is given as follows −The kernel is the most privileged part of the computer system. There are some privileged instructions that can only be executed in kernel mode or supervisor mode. The the privilege reduces for device drivers and applications respectively.Features of Supervisor ModeSome of the important features of supervisor mode are as follows −Supervisor mode ... Read More

There are two modes of operation in the operating system to make sure it works correctly. These are user mode and kernel mode.They are explained as follows −User ModeThe system is in user mode when the operating system is running a user application such as handling a text editor. The transition from user mode to kernel mode occurs when the application requests the help of operating system or an interrupt or a system call occurs.The mode bit is set to 1 in the user mode. It is changed from 1 to 0 when switching from user mode to kernel mode.Kernel ... Read More

An operating system is a construct that allows the user application programs to interact with the system hardware. Since the operating system is such a complex structure, it should be created with utmost care so it can be used and modified easily. An easy way to do this is to create the operating system in parts. Each of these parts should be well defined with clear inputs, outputs and functions.Simple StructureThere are many operating systems that have a rather simple structure. These started as small systems and rapidly expanded much further than their scope. A common example of this is ... Read More