Operating Systems

1. It is a Primitive Operating System.

2. Usually in low memory where interrupt vectors are placed.

3. It Isolate user from physical address space using logical address space

QNX is free for personal use. Commercial licenses vary in price for runtime (installed) copies.

The types of geomorphic systems are open and closed geomorphic systems.

Operating systems began in the early days of computing, primarily to manage hardware resources and provide a user interface for interacting with computers. Initially, computers were operated manually, but as they became more complex, the need for software to manage processes, memory, and input/output operations emerged. The first operating systems were simple, with batch processing capabilities, evolving over time into more sophisticated systems that allowed for multitasking and user interactivity, such as UNIX in the 1970s. This evolution laid the foundation for modern operating systems we use today.

Yes

True!

jhy

# Open Active Directory Sites and Services. # Expand the site name in which the standby operations master is located to display the Servers folder. # Expand the Serversfolder to see a list of the servers in that site. # Expand the name of the server that you want to be the standby operations master to display its NTDS Settings. # Right-click NTDS Settings, click New, and then click Connection. # In the Find Domain Controllers dialog box, select the name of the current role holder, and then click OK. # In the New Object-Connection dialog box, enter an appropriate name for the Connection object or accept the default name, and click OK.

Absolutely. Just because the OS is generally real time and kernel priority doesn't mean that a user process can't use a semaphore. After all there are real time user processes and they need to signal or block each other. And user processes can get into a deadly embrace situation as well; it doesn't mean the computer is down, but the user processes are stuck and will have to be killed in order to get out of the deadly embrace.

Dual-boot means that you use two operating systems on one computer. Multiboot refers both to having several operating systems (usually more than three) on a computer, and to an operating system having built-in support for a bootloader that can load multiple operating systems (Linux, FreeBSD, and Solaris are all multiboot compliant, since they can accept kernel parameters directly from GRUB).

An operating system is the system working on the computer. Linux and Windows are both operating systems used in businesses.

PC-DOS, Apple, UNIX

haha poopy

Graphical User Interface

The program could maximize the CPU time allocated to it by not fully utilizing its time quantums. It could use a large fraction of its assigned quantum, but relinquish the CPU before the end of the quantum, thereby increasing the priority associated with the process.

The feudal system was a hierarchical social and economic structure that dominated medieval Europe, characterized by the exchange of land for military service. In this system, kings granted large estates to nobles (lords) in return for loyalty and soldiers, while peasants or serfs worked the land in exchange for protection and a place to live. This arrangement created a rigid class system, with the monarch at the top, followed by nobles, knights, and peasants. The feudal system declined with the rise of centralized monarchies, trade, and urbanization.

In operating systems and other multithreaded, event-driven, or low-level software, it is possible to have event-handling or interrupt-handling code that is called every time an event or interrupt is triggered by hardware or software. If an event triggers a call to the handler, then the code will context switch to "enter" that method. Once in the method, suppose that it accesses a set of static structures in memory, so that they can be modified (like a counter or a routine that reads and updates the data). Now, suppose that another thread or process triggers an event to call the same method. This will enter the same handler method at the same time (a reentrant block of code). Well, while the first method is still accessing the static memory location, the second thread/process will be entering the same method to do the same thing, and they will attempt to modify the same area of memory at the same time. This is called a race condition. In order to prevent this from happening, memory management in the OS kernel should "lock" the memory location so that no other processes can overwrite that memory at the same time. They will encounter the lock and will either wait until the locked memory has been unlocked by the first routine, or they will exit. Typically, if locks are not accounted for, and two threads are dependent upon each other, a deadlock condition can also be reached, which freezes the system.

Ø In a paging system, programs and data stored on disk are divided into equal, fixed sized blocks called pages, and main memory is divided into blocks of the same size called frames. Exactly one page can fit in one frame.

Physical memory is divided into parts called FRAME and logical memory is divided into parts called PAGE.

because the process holding the spinlock would do nothing (thus wasting CPU cycles) when it is allocated the CPU. It is better to put it in the sleep state (that is putting the process in the waiting queue). As soon as the process is wakened up (by some other process/thread invoking "signal/wake" on it) it is put in the "ready" queue when it runs as soon as the CPU is assigned to it.

on multiprocessor systems, it's generally better to "spin" because it is assumed that the running process on the other processor will release the lock pretty soon (thus it can release the lock and still continue running while your thread/process is getting a hold of the lock).

for better explanation check out "Operating System Concepts" by Silberchatz,

also Cornell University slides on Operating Systems Course are pretty useful as well.

The king of Spain in the 15th century installed it to get tax money from the Indians in present day Mexico and southern America

try links on qnxforum.com

It is called multi-tasking or multiple use.