Elements of an Electronic Data Processing (EDP) System

A.  HARDWARE.  Refers to the physical equipment or components of an electronic data processing system.

Separate devices that constitute a hardware:

1. Memory system where data and instructions are stored.
2. Input/output devices for communication with the environment of the system.

FOUR TYPES OF FUNCTIONAL UNITS

1. CENTRAL PROCESSING UNIT - The "brains" of the computer system.

A.  Control Unit - supervises or monitors the functions performed by the entire computer system according to conditions set forth by the stored program.

B. Arithmetic/Logic Unit - performs operations such as addition, subtraction, multiplication, and division, as well as moving, shifting, and comparing data.

C.  Memory Unit - somewhat like an electronic filing cabinet capable of holding data or instructions.  THis unit is a random-access storage device consisting of thousands of storage locations, each of which can be directly reached by the control unit.

Memory is required by the computer because

1. The data need to be stored in order to be available when it is required.
2. The instruction need to be stored so that they can be used again and again without having ot enter them each time through the input unit.

OPERATIONS PERFORMED BY THE CPU

1. Input Operation - the CPU signals an input device to read data.

2. Processing Operation

• Data transfer Operation - it can move data from the input area to the output area.
• Arithmetic Operation - it can add, multiply, subtract, and divide quantities.
• Logic Operation - It can test or perform simple decisions such as determining if a number is less than, equal to, or greater than another.

3. Output Operation - causes information to be transmitted from the Output area, provided for by each program, to an Output device where it is written out or recorded.

2-3.. INPUT/OUTPUT UNITS.  These are used to provide a link between the machine and its users.  There units feed data into and retrieve data from the CPU.

Two types of primary storage

1.  Internal Memory - contained in the silicon chip and can hold instructions and data which the computer is currently working on or information which the CPU needs to work very rapidly because the speed of the CPU is very high and acquired information to be readily available.

2 types of memory chips

1. ROM CHIP - Read Only Memory chip.  It never forgets and the information stored can only be read but cannot be added or rubbed out.
2. RAM CHIP - Random Access Memory chip.  New information can be recorded, read then rubbed out when no longer needed.  Once the computer is switched off, RAM forgets everything.

2.  External Memory - information written in this form stays forever and can be wiped off and the same area can be used to store new information.

4.  AUXILIARY OR SECONDARY STORAGE UNIT - e.g.  Tape backup, Diskettes, Hard Disk ,Compact Disk

B. SOFTWARE - all programs that govern the operation of a computer and make the hardware runs.

Two general categories of software:

1.  Application Software - the general term for programs that perform specific user-oriented tasks, such as word-processing and spreadsheet applications.

2.  Systems software - the general term for programs that direct hardware-related tasks.

     Operation System - the collection of program that supervise all the activity takes place within a computer.

C.  PERSONNEL - refer to the people who work with the computer so that it can be used to find solutions to problems, and also refers to the persons who use the information generated by the computer.

[ source: Philippine Copyright 2008 by HYDN Publishing PART 1 Fundamentals of Computer Literacy ]