In the 1960s, operating systems were developed to help overcome this problem. An
operating system is a collection of programs used by the computer to manage its own
operations. By eliminating the human operator, the operating system can run the jobs
at computer speeds. This avoids CPU idle time while increasing utilization of computer
operating system: a collection of programs that permits the computer to
manage itself, reduces CPU idle time, and increases utilization of computer
3-12. TYPES OF OPERATING SYSTEMS
There are two basic types of operating systems: batch and real time. In batch
jobs, several user programs are grouped into a batch and processed one after another
in a continuous stream. A real time operating system can respond to spontaneous
requests for system resources, such as management inquiries from terminals.
3-13. BATCH PROCESSING
a. Description. Most data processing is done using batch processing (also
know as serial, sequential, or off-line processing). Batch processing involves
processing transactions on the computer at specified times. Payroll, for example, is
normally processed in batch mode. On a predetermined date at a predetermined time,
the variable information about payroll (hours worked, changes in deductions, new pay
rates, new employees, etc.) is entered and the computer produces all of the payroll
checks and information at the same time. The payroll information is allowed to
accumulate and entered as a batch or group at a central computer site or other location
(a small hospital that is a client of a computer service, another branch office or
batch processing: also called serial, sequential, or off-line processing; a
technique in which a number of similar items or transactions are accumulated
and then processed periodically as a group or batch.
(1) In batch processing, the data are first sorted in the same sequence as
the master file, and then master files are accessed sequentially, rather than skipping
around (direct access).
sort: to place a group of records into a desired sequence.
(2) The sorting may be done off-line, that is, before the data are entered into
the computer. For example, if sorting a group of punched cards, a high-speed sorter
may be used before the data are entered into the computer.
off-line: operations performed apart from the computer.