Time Sharing System
Batch operating system have some drawbacks to overcome these problems a system was introduced which is called as time sharing system. In case of multiprogrammed batched systems environment, it provides proper and effective utilization of several resources such as memory, CPU and peripheral devices. According to the user point of view there were some difficulties in bathed system. Since the user was not capable to interact with job during its execution. User required to set up the control card to handle all the possible outcomes. Subsequent steps may depend on the results of previous one in case of multistep job. It can be difficult to define entirely what to do in all the cases. Another problem was that the programs must be debugged statically from snapshot dumps. If programmer wanted to study the behavior of a program so, he cannot modify a program as it executes.
Time sharing system which is also called multitasking. Time sharing system is generally a logical extension of multiprogramming. CPU executes multiple jobs by switching between them. Users may interact with each program while it is running because, frequent occurrence of switches. An interactive system is basically a computer system which delivers online communication between system and user this system is also called as hands-on system. In time sharing system user directly gives instruction to the operating system or program and receive a quick response immediately. Keyboard is use to give the inputs and a display screen usually CTR or monitor to offer the output. The operating system seeks for next command statement after the execution of current job for this situation key board is used rather than the card reader.
The user gives command and wait for response then take decision for next command on the basis of the previous result. User can see the results immediately. For entering program, the system has an interactive text editor and an interactive debugger for supporting in debugging program. To access the data and code there must be an online file system, file or data file is a collection of alphabets, numeric and alphanumeric. Time sharing system provides interactive use of computer system at the reasonable cost. In time shared operating system CPU use scheduling and multiprogramming to allocate every user with a small portion of a time shared computer. At least one program user can have in memory. A time shared system allows the multiple users to share the computer simultaneously.
In time shared system each command or action tends to be very short only little time is wanted for each user. It makes sense that every user is using the separate computer while a computer is being shared among the multiple users. It required more memory to keep the multiple programs in memory simultaneously, virtual memory is used to achieve this goal. For concurrent execution time sharing system provides a mechanism for which sophisticated CPU scheduling schemes are required. This system is competitively better then batched system whoever it is costly as well. Time sharing and multiprogramming is the central theme of advance operating system.