Simple Batch Systems:
The Major Task of the OS is to transfer the control automatically from one job to the next. The OS will always reside in
memory.
To spend-up processing jobs with similar needs are batched together and were run through the computer as a group. The output
from each job would be sent back to the appropriate programmer. The programes will be stored in to batches with similar
requirements.
The definitive feature of a batch system is lack of interaction between the user and the job while that job is executing.
The job is prepared and submitted at later time, the output appears. The delay between job submission and job completion is
called tumaround time. May result from the amount of computing needed or from delays before the OS Stars to process the job.
In this execution enviroment, the CPU is often idle. This idleness occurs because the speeds of the mechanical input output
devices are slower than those of electronic devices.
Improvement is technology resulted in faster I/O devices unfortunately, CPU increased even faster, so that the problem was
not only unresolved, but also exacerbated.
The introduction of disk technology has improved the CPU speed. Rather than the cards being read from the card reader
directly into memory and then the job being processed, cards are read directly from the card reader on to the disk.
The location of card images is recorded in a table kept by the operating system, when a job is executed, OS satisfies its
requests for card reader i/p by reading from the disk. Eg. when the job that line is copied into a system buffer and is
called spooling the acronym for simuldaneous peripheral Operation on-line.