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Unformatted text preview: ay in executing his/her commands and will
normally feel that he/she is the sole user of the system. In this manner, each user is
given the impression that he/she has his/her own computer, whereas actually a
single computer is shared among many uses.
Requirements of Time-sharing Systems
Time-sharing systems typically require the following additional hardware and
1. A number of terminals simultaneously connected to the system so that
multiple users can simultaneously use the system in interactive mode.
2. A relatively large memory to support multiprogramming. 3. Memory protection mechanism to prevent one job's instructions and data from
other jobs in a multiprogramming environment.
Job status preservation mechanism to preserve a job's complete status
information when the CPU taken away from it and restoring this information back
before the CPU is given back to it again.
5. A special CPU scheduling algorithm that allocates a very short period of CPU
time one-by-one to each user process in a circular fashion.
6. An alarm clock mechanism to send an interrupt signal to the CPU after every
Advantages of Time-sharing Systems
Although time-sharing systems are complex to design, they provide several
advantages to their users. The main advantages of time-sharing system are as
Reduces CPU idle time. It will be waste of precious CPU time to allow a
single user to use a large computer interactively because his/her speed of thinking
and typing is much slower than the processing speed of a computer. While a
particular user is engaged in thinking or typing his/her input, a time-sharing
system can service many other users. In this manner, time-sharing systems help in
reducing the CPU idle time to a great extent, increasing the system throughput.
Provides advantages of quick response time. The special CPU scheduling
algorithm used in time-sharing systems ensures quick response time to all users.
This feature allows users to interact with the system more rapidly while worki...
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This document was uploaded on 04/07/2014.
- Spring '14