Multitasking - Single Processor Many Users Many Tasks
In multitasking or also called time sharing systems multi user more than one users are sharing one processor at a time. This type of systems is shown in figure several dumb terminals without processor are connected to a powerful computer usually mini or mainframe through wires if in the same office or telephone line. The speed of user is much slower as compared to the computer. Hence the computer can server many users on the timesharing basis. Computer works on the program of the 1st user for suppose 20 milliseconds then works on 2nd user program of r 20 ms then processes on 3rd user program for next 20 ms and so on and then comes back to the 1 user program in few ms after serving all the user and the cycle is repeated. Each user in the system feels that he is the only user using the computer. Ticket reservation systems may be an example of such systems.
The drawbacks of systems are:
A. If the computer has nay problem and not working the whole systems will crush to halt.
B. .As the number of users of increase time taken to complete one cycle to responding all uses also increases. People will have to wait for their turn.