TOPIC 1—COMPUTER FUNCTIONS
AND TYPES
The computers the Navy uses vary from
mainframes to microcomputers.
Regardless of the
types of computers and their operational uses, their
functions are basically the same. Depending on the type
of computer and the operational use, the methods will
vary. First, we discuss the functions of computers, the
different ways computers handle data, and the methods
they use to accomplish this. Then we discuss the
functional operation of computers.
COMPUTER FUNCTIONS
All computers must be able to gather, process, store,
disseminate, and display data.
Gather Data
All computers, no matter what their size, must gather
data before they can process the data. The operational
program will dictate how the data is gathered—
manually, automatically, or a combination of both.
Manually, an operator or technician will input the
data to the computer. This can be done either directly
or by a device external to the computer. The following
are commonly used input devices:
l Keyboards
. Display consoles
. Data terminals
l Computer maintenance panels
l Storage devices (magnetic tape units, disk drive
units, and paper tape units)
As an example, an operator at a console will input data
via the console to the computer and the computer will
process the data for storage, dissemination, or display
depending on the functions of the operational program.
Data may be input from a console using pushbuttons,
switches, toggles, or a combination of these.
Automatically gathering data means the computer
receives data from another system, subsystem, or
equipment.
The computer monitors for external
requests through a series of programmed requests and
acknowledges. The computer first sees the gathered
data when it comes through the input section of the
input/output section of the computer. Then depending
on the operational program, the computer will either
react immediately or store the data for future use. The
following are examples of the sources from which
computers gather the data automatically:
Systems such as the fire control system
Subsystems such as the combat direction system
Data processing systems (another computer and
conversion devices)
Display systems via sensors (radar)
Communication systems such as data links and
local-area networks (LANs)
Many computer systems are designed to gather data
using a combination of both the manual and automatic
methods.
Process Data
Processing data is the main function and the
purpose of the computer. There are other systems,
subsystems, and equipment that will work with the
computer to help gather, store, disseminate, and display
data; but processing the data is exclusively the
computer’s function. The heart of the computer—the
place where the data is processed in a computer—is
called the central processing unit (CPU). Figure 1-1
shows the basic configuration of a digital computer.
After the data is processed, it can be stored,
disseminated, or displayed.
Store Data
The computer can store data either internally or
externally. Internally, the computer uses memory
Figure 1-1.—A basic functional composition of a digital
computer.
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