Time Sharing
Evolution of Operating Systems
• Serial Processing:
– No operating system
• Machines run from a console with display lights, toggle switches, input device, and printer
• Schedule time, e.g. sign up
• Setup included loading the compiler and source program, saving compiled program, loading and linking
• Simple Batch Systems
– Monitor
• Software that controls the sequence of events
• Batch jobs together
• Program branches back to monitor when Finished
Job Control Language (JCL)
• Special type of programming language
• Provides instruction to the monitor, e.g.
– What compiler to use
– What data to use
· Uniprogramming
• Processor must wait for I/O instruction to complete before preceding
· Multiprogramming
• When one job needs to wait for I/O, the processor can switch to the other job
· Time Sharing
• Using multiprogramming to handle multiple interactive jobs
• Processor’s time is shared among multiple users
• Multiple users simultaneously access the system through terminals
Posted By-: Vissicomp Technology Pvt. Ltd.
Website -: http://www.vissicomp.com