Multi User Operating Systems

An operating system is a set of software programs, which manage computer hardware in a controlled fashion. The operating system controls the file-system, process management, memory management and peripherals.

Multi-user operating systems are used on large mainframe computers. A mainframe computer system has one very powerful processing unit, which may contain many microprocessors. Many users will all share this processing unit. They use terminals (a keyboard and a monitor) to access the mainframe computer.

A multi-user operating system lets more that one user work on a mainframe computer at the same time.

Features of a MUOS

The main features of multi user operating systems are resource sharing, multi tasking and background processing.

·         Using resource sharing in a multi-user operating system allocates the CPU time of the mainframe computer between the different users. Each user in turn is given a small time slice of the CPU time. Because these time slices are very small the users believe that they are all using the mainframe at the same time.

Resource sharing also lets users share peripherals such as printers or hard drives and also lets users share files on a network.

·         Multi-tasking lets the operating system run more than one program at a time. One example of a multi tasking could be editing a word document while browsing the Internet. The way this is done is by the processor using time slicing.

·         Background processing is a term which means when commands are not processed straight away but rather executed "in the background", often while other programs are interfacing with the system in real time.

Types of MUOS

There are three main types of multi user operating system. These are distributed systems, time sliced systems and multi processor systems.

·         In a distributed system, to the user it appears to...