- Computer systems of the 1960’s used card reader and punch cards as the primary input medium. The primary output devices were line printers, tape drives and punch cards.
- In these type of system user did not interact directly with computer system. Users prepare a job (which consists of program or data) and submit it to the computer operator. A batch is a sequence of user jobs. Each job is independent of other jobs in the batch. Jobs typically belong to different users. The job was usually in the form of punched cards.
- A computer operator forms a batch by organizing a set of user jobs in a sequence and inserting special marker cards to indicate the start and end of the batch and submits it to the batch processing system to process it.
- The primary function of the batch processing system is to transfer control automatically from one job to the next job without intervention of the computer operator.
- Batch processing is implemented by the kernel (batch monitor) which resides in one part of the computer’s memory and it executes the job sequential.
- To speed up processing, the operator would sort the programs into batches with similar requirements and submit it to the computer and it would run each batch.
- At the end of the batch, it performs batch termination processing and waits for the operators to initiate next batch thus the operator needs to intervene only at the start and end of a batch.
- In this type of operating system the CPU is often ideal because the speed of mechanical input/output devices is slower than CPU.