fundamental of computers
DESCRIPTION
information system managementTRANSCRIPT
Fundamentals of Computer
Computer is a data processing machine which is derived from human intelligence, for processing it has to perform the following task:
Accept data from user (Input) Accept instructions from user (Input) Convert data into instruction (Processing) Display the result (Output)
What is Computer
Input processing outputData
Instructions Output
information
Garbage In Garbage Out
GIGO
Fast in processing, storage and retrieval
Large storage space Accurate Versatile Works automatically Diligent Compactness
Characteristics/limitations of computers
No intelligence No decision power Cannot learn with
experience
Characteristics Limitations
Digital Computer: Accepts digits and alphabets, works upon discrete data (0,1) Ex: Mini, micro, mainframe and super computers used business purpose
Analog Computers: Using signals as input, Operate by measuring rather then counting mostly used in scientific or engineering application Ex: thermometer, speedometer, voltmeter, Complex scientific calculation
Hybrid Computers: Use signals and digits as input, special purpose computers Ex: Used in hospitals to know the radio activity level & ICU used in mines, chemical processing.
Classification of computer
Block Diagram of Computer
Input
Control unit
ALU
Memory
Output
Central Processing Unit
CPU: Brain of computer to control all inputs Process the instructions, perform arithmetic and logical operations, data flow with in the computer, communicate with input and out units ALU: Electronic circuit, Arithmetic operations like +,-,*,%,
CU: Electronic circuit, to control the activities of the computer
Memory: active part to store, process and deliver the data when required
Central Processing Unit
2 types : primary memory Secondary memory
Primary memory 2 types 1. random access memory 2. read only memory Read only memory (ROM): data resides permanently, non
volatile, stores the program which is required to run the computer EX: Operating system, boot strap loader
Random access memory (RAM): data required by the program is stored in RAM, temporary memory, volatile, random access, also called as read/write only memory,
Expensive memory
Memory
Secondary memory:
called as external memory or main memory, high speed, Low cost, cost per bit is low,Ex: magnetic disk, magnetic tape, floppy disk, hard disk, CD
ROM, zip disk, Winchester disk, optical disk.
Memory
Smallest unit: bit 0,1
1 byte=8 bits 1024 bits=1 kilo byte 1024 bytes=1 mega byte 1024 megabyte=1gigabyte 1024 gigabyte=1 terra byte
Unit of Memory
Input: the process of entering and transforming data into machine readable form so that it can be processed by the computer.
Keyboard Joy stick Mouse MICR (Magnetic ink character recognition) OCR (Optical character reader) OBR (Optical bar code reader) Web camera Scanner
Input units
Out put devices: Electromechanical devices, accept data from computer and transfer into output device.
Monitors Printers Plotters Screen image projectors Voice response system.
Output Devices