Batch Processing System
is the sequential execution of a series of jobs on a computer. Batch means programmers wrote code on paper forms which would be
keypunched onto paper tape. The tape would then be passed to the system operator who would schedule the task and phase supply
the program into the computer.
What will happen with a number of tasks?
A number of tasks would be 'batched'. These tasks were referred to as "batch jobs". The batch jobs would be scheduled on a timetable, and could
be begins automatically or manually by the operator.
Benefit
Batch processing system is controlling the load placed on the computer by careful scheduling.
Example
A long processor-intensive task would be timed to run over-night allowing for timesharing usage or short jobs during the day. When a batch
job begins, processing will usually continue until it is completed unless there is an error but some mainframe machines could process
multiple batched jobs in sync.
Time Sharing System
Is an approach system to interactive computing in which a single computer is used to provide apparently simultaneous interactive
general-purpose computing to multiple users by sharing processor time.
Why we need time sharing system?
Because early mainframe computers were extremely expensive, it was not likely to allow a single user select access to the machine
for interactive use. This is because computers in interactive use often spend much of their time lazily waiting for user input; it was
planned that multiple users could share a machine by using one user's unoccupied time to service other users. Similarly, small slices
of time spent waiting for disk and tape could be granted to other users. Computers capable of provide time-sharing services would usually
operate in batch mode overnight.
These solutions alone were not enough to build a fully handy time-sharing system. In order to provide smooth service to multiple users,
a time-sharing system needed a way to deal with many processes so that did not often pause for input/output. This central hardware interrupt
system capable pausing a running process, and giving processor time to another process.
Process Based System
-Is design of micro processors to handle different processes. This system gave origin to the modern day operating system. It allows concurrent
running of programs and applications which makes it higher to the time sharing as it handles more similar tasks at a time "Multiprogramming".
It was faster than the time sharing system.
Real Time Based System
An RTBS is real time software that manages the time of a microprocessor to ensure that all time critical events are processed as efficiently as
possible. An RTBS simplifies the design process of the system because it allows the system to be divided into multiple independent elements
called tasks. A task is a simple program, which thinks it has the microprocessor all for itself. Each task is given a priority based on its importance.
The design process for a real-time system consists of splitting the work to be done into tasks, which are responsible for a portion of the problem.
The microprocessor still has the same amount of work to do but, now the work can be prioritized and it will be under user control. An RTBS also
provides valuable services to application such as time delays, system time, message passing, synchronization, mutual-exclusion and it should be
rich in inter process communication capabilities.
