Components of an Information System (Hardware & Software)

Components of an Information System (Hardware & Software) 

INTRODUCTION TO HARDWARE 

• Hardware: any machinery (most of which use digital circuits) that assists in the input, processing, storage, and output activities of an information system. 


• When making hardware decisions, businesses must consider how hardware can support: 

• Objectives of the information system 
• Goals of the organization 
• Choosing the right computer hardware requires understanding its relationship to the information system and needs of the organization. 

HARDWARE COMPONENTS 

1. Input devices 
2. Output devices 
3. Processing devices (CPU, GPU, Motherboard, Sound card, Network card) 
4. Storage devices: 
         • Primary storage devices 
         • Secondary storage devices 




INPUT AND OUTPUT DEVICES 

• Through input and output devices, people provide data and instructions to the computer and receive results from it. 

• Selection of input and output devices depends on organizational goals and IS objectives. 

01. INPUT DEVICES 

• Any computer hardware part that facilitates feeding of data and information into a computer system falls under the input device category.  

• Input devices read user input actions including text, graphics, sound, video and other digital inputs before converting them into digital signals.  


• The input is then manipulated by the processor. 

• The following is a list of commonly used input devices: 
 • Keyboards 

• Pointing devices: (Control the movement of a cursor on a computer screen) 


- Mouse 
- Touchpad 
- Touchscreen 
- Multi touch screen 
- Pen input - Motion sensor 
- Graphics tablet 
- Interactive smart board 



• Game controller devices: 
- Joystick                    
- Steering wheel 
- Gamepad  

• Audio input devices: 
- Microphone 
- Midi keyboard (piano-style user interface keyboard device ) 

                         




• Visual and Imaging devices: 
  
Digitizers (Photo and Video):  

- Webcam 
- Digital camera 
- Digital camcorder 
- Voice-recognition systems 
- TV capture card 
- Scanner 
- Barcode reader                               

• Terminal Entry:  
 
- Point of Sale (POS) Terminal 
- Dumb Terminal 
- Smart Terminal 
- Intelligent Terminal 
- Automated Teller Machine 



• Source / Direct Data Entry Devices:  

- Barcode Reader 
- Smart Card 
- Optical Mark Recognition (OMR) 
- Sensors 
- RFID (Radio frequency identification) 
- Optical Character recognition (OCR) 
- Magnetic Ink Character Reader (MICR) 
- Biometric Input  


02. OUTPUT DEVICES 

• Any computer hardware component that facilitates dissemination of data into usable form is classified under the output device category.  

• Output devices display information like text, graphics, video, sound and other digital outputs. 




• Display output 

• Monitor 
• Projection display                          
• Electronic smartboard 
• Flat Panel Displays: LCD (Liquid Crystal Display), Electroluminescent Display (ELD) 
• Electrophoretic Display (ED) and Plasma 
• CRT (Cathode Ray Tube) and Televisions 
• Graphics Adapter / Video Card 
• TV Card 

• Sound output 

• Speaker 
• Headphone and earphone 
• Fax machines 
• Photocopy machines  
• Printers 
• Impact printer 
• Dot matrix printer 
• Non impact printer                                 
• Inkjet printer 
• LaserJet printer 
• thermal printer 
• Plotters 




03. PROCESSING DEVICES 

• System unit 
• Houses the components responsible for processing (the CPU and memory).  
• All other computer system devices are linked either directly or indirectly into the system unit housing. 


CENTRAL PROCESSING UNIT (CPU) 

• It is also known as processor, central processor or microprocessor. • A computer's CPU handles all instructions it receives from hardware and software running on the computer. 

Basic elements of CPU:  

• The ALU (Arithmetic Logic Unit) that performs mathematical, logical, and decision operations. 

• The CU (Control Unit) that directs all of the processors operations. 

• Registers, which hold instructions and other data. Registers supply instruction to the ALU and store the results of operations. 

• L1 and L2 cache memory. Takes less time to retrieve data from cache when compared to get data from random access memory (RAM). 

CENTRAL PROCESSING UNIT (CPU) 

• A CPU has four primary functions: fetch, decode, execute, and writeback. 

• Fetch: CPU retrieves the instruction that it needs to run from memory. Each instruction in a program (which contains millions of instructions) is stored at a specific address. 

• Decode: The instruction that the CPU fetches from memory is used to determine what the CPU should do. The instruction is broken down into parts (Decode instructions into commands).  

• Execute: CPU performs one of the following steps in this stage: 

• Calculations [using ALU] • Moving data from one memory location     to another • Jump to different addresses in the     program based on decisions  

• Write-back:  This stage usually produces     output & this output is written to computer’s     memory. 

TYPES OF MEMORY & MEMORY HIERARCHY 


                        





MEMORY TYPES  AND STORAGE DEVICES 



                     

PRIMARY MEMORY: REGISTERS 


• A high-speed storage area in the CPU used to temporarily hold small units of program instructions and data immediately before, during, and after execution by the CPU. 

• The CPU processes data and instructions with high speed, there is also movement of data between various units of computer. 

• It is necessary to transfer the processed data with high speed. 

• So the computer uses a number of special memory units called registers. 

PRIMARY MEMORY: CACHE MEMORY 



• A Cache is a small and very fast temporary storage memory. 

• Cache Memory is a small memory chip is attached between CPU and Main memory. 

• It is designed to speed up the transfer of data and instructions. 

• It is faster than RAM and the data/instructions that are most recently or most frequently used by CPU are stored in cache. 

                  


PRIMARY MEMORY: MAIN MEMORY 


• Commonly known as Random Access Memory or just RAM. 

• Located physically close to the CPU, but not on the CPU chip itself.  

• Holds instructions and data needed for programs that are currently running. 

• Rapidly provides data and instructions to the CPU. 

                   


SECONDARY STORAGE 

• Offers the advantages of non-volatility, greater capacity, and greater economy. 

• Secondary storage is a storage medium that holds information until it is deleted or overwritten regardless of the computer has power. 

SECONDARY STORAGE DEVICES AND THEIR CLASSIFICATION 

                         



SECONDARY STORAGE DEVICES 


• Magnetic Disks/Hard disks 

• Hard disks provide faster access to data than floppy disks, magnetic tape and are capable of storing much more information. 

• Magnetic Tapes 

• Cheapest storage medium 

• Can handle enormous amount of data 

• Slowest for retrieval of data 

• Optical Disks 

• High capacity (more than 600MB can be stored in a disk), low cost and high durability.  

• Floppy Disks 

• Slower than hard drives - less capacity - less cost 

• Big advantage is portability \

Secondary storage Devices

(1) Magnetic tapes 
(2) Magnetic disks 
(3) RAID (Redundant Array of  Independent/Inexpensive Disks) 







 







(4) Optical Disks 
(5) Memory Cards 
(6) Flash Memory 
(7) Floppy Disks 

COMPUTER SYSTEM TYPES 

• Portable computers 

– Laptops 
– Handheld computers Handheld computers (Ex: Personal Digital Assistants [PDAs]. PDAs are also called palmtops and pocket computers. 
– Notebooks 
– Tablets 
– Smart phones 

• Thin client  

– low-cost, centrally managed computer with essential but limited capabilities and no extra drives, CD or DVD drives, or expansion slots. 
– Thin clients connected to their server via a computer network. 
– Designed to serve as the clients for client/server architectures. 

• Desktop (Personal Computer) 

• Workstation computer 

Workstations are high-end, expensive computers that are made for more complex procedures and are intended for one user at a time. 

• Mini computer 

It is a midsize multi-processing system capable of  supporting up to 250 users simultaneously. 

• Mainframe computer 

Mainframe is very large in size and is an expensive computer capable of supporting hundreds or even thousands of users simultaneously. 

• Super computer 

• One of the fastest  and most expensive computers currently available. These huge computers are used to solve very complex science and engineering problems.  

AN OVERVIEW OF SOFTWARE 


Systems software:  

• Set of programs that coordinates the activities of hardware and programs. 
• Application software: 

• Helps users solve particular problems 
• In most cases, application software resides on the computer’s hard disk 
• Application software can also be stored on CDs, DVDs, and flash or keychain storage devices.

SYSTEMS SOFTWARE  

• Systems software 

• System software is computer software designed to operate and control the computer hardware as well as to run application software, such as Web browsers, media players and office suites.  


Types of systems software 
• Operating systems 
• Utility software 

SYSTEMS SOFTWARE: OPERATING SYSTEMS  

• Operating system (OS): a set of computer programs that controls the computer hardware and acts as an interface with application programs. 

FUNCTIONS OF AN OPERATING SYSTEM 

                          

SYSTEMS SOFTWARE: UTILITIES 

• In computers, a utility is a small program that provides an addition to the capabilities provided by the operating system. 

• A utility is a special and nonessential part of the operating system.  

• Utility programs often come installed on computer systems. It is also possible to purchase a number of utility programs from the market.  

• Common types of utility programs: 

• Hardware utilities 
• Virus-detection and recovery utilities 
• File-compression utilities 
• Spam and pop-up blocker utilities 
• Network and Internet utilities 
• Server and mainframe utilities 


APPLICATION SOFTWARE 


• Primary function is to apply the power of the computer to give individuals, work groups, and the entire enterprise the ability to solve problems and perform specific tasks. 

• Application programs interact with systems software; systems software then directs computer hardware to perform the necessary tasks.