about mobile computing

 Mobile Computing

Mobile computing is human–computer interaction by which a computer is expected to be transported during normal usage. It allows us to transfer data like audio or video from a computer/device to any other computer without any physical connection. Here it uses waveforms to have communication. We can use any device for this communication.

Features:

1. Portability Ability to move a device within a learning environment or to different environments with ease.

2. Social Interactivity Allows for data sharing and collaboration between users.

3. Connectivity Ability to be digitally connected for the purpose of communication of data in any environment.

4. Individuality Ability to use the technology to provide scaffolding on difficult activities and lesson customization for individual learners.

    Examples: Tablet PC, Mobile, etc.

  Advantages:

1.      Increase in Productivity- Mobile devices can be used out in the field of various companies, therefore reducing the time and cost for clients and themselves.

2.      Entertainment- Mobile devices can be used for entertainment purposes, for personal and even for    presentations to people and clients.

3.      Portability- This would be one of the main advantages of mobile computing, you are not restricted to one location in order for you to get jobs done or even access email on the go

4.      Cloud Computing- This service is available for saving documents on a online server and being able to access them anytime and anywhere when you have a connection to the internet and can access these files on several mobile devices or PCs at home.

Disadvantages:

1.      Quality of connectivity- as one of the disadvantages, mobile devices will need either WiFi connectivity or mobile network connectivity such as GPRS, 3G and in some countries even 4G connectivity  that is why this is a disadvantage because if you are not near any of these connections your access to the internet is very limited.

2.      Security concerns- Mobile VPNs are unsafe to connect to, and also syncing devices might also lead to security concerns. accessing a WiFi network can also be risky because WPA and WEP security can be bypassed easily.

3.      Power Consumption- Due to the use of batteries in these devices, these do not tend to last long, if in a situation where there is  no source of power for charging then that will certainly be a let down.

On the basis of model

 We have following types on the basis of model

1.)XT computers

2) AT computers

3)PS/2 computers

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Let's know in detail.

1.)XT computers

    Features:-

            :

1. has same features as of IBM except minor improvements

2. used 8086/8088 microprocessor with speed 4.77 MHZ

3. had one supporting co-processor(math)

4. it had 128KB RAM, 10MB hard disk

5. the operating system was DOS

6. used programs concept stored in ROM

7. for programming, BASICA was used

8. many devices like keyboard,joystick, printer,floppy disk were used

9. to enhance the video quality, video adapter was used. later it was changed to ‘enhanced graphics adapter

10. gradually the input channel, RAm capacity  and others’ quality was improved.

2) AT computers

    Features:-

    

1. used improved technology; so called advanced technology over XT.it was developed by IBM

2. used 80286 microprocessor with speed 8MHZ

3. the system board had 16-bit bus and 24-bit address bus

4. it used 15 IRQ and 7 DMA channels

5. used maximum memory 16MB

6. input with 84-keyed board

7. storing devices floppy of capacity 1.2MB, hard disk of 20MB were used

8. was equipped with video cards

9. used operating system DOS with an additional feature  of networking

10. was available with physical lock system

just like XT, AT had also  supporting co-processor(math).

3)PS/2 computers

    Features:-

        

1. next generation computer released by IBM to recapture the growing market in the field of pc

2. it had complex architecture (microchannel) than XT and AT

3. computers used Intel 286,386SX, 486 etc processors.

4. had 8MHZ or faster speed

5. primary memory as semiconductor with capacity 512K (72 pin system)

6. secondary media as hard disk with capacity 20MB and floppy disk of capacity 720K to 1.44MB

7. VGA was used for high resolution video and colours

8. used with GUI operating system named OS/2 and UNIX in all its pcs

9. inputs like keyboard having 101 keys and mouse were used in its interface.

10. supported ‘plug n play’ architecture

11. used BIOS based programs

12. IBM also had developed same architecture based server for multiprocessing.

on the basis of brand

 On the basis of brand we have mainly three computers as given below.

1.)IBM computers

2.)IBM compatible

3)Apple/Macintosh

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Let's know in  detail.

1.)IBM computers

        Features:

        Features:

1. powerful computer developed by IBM

2. uses XT technology

3. uses 8088 intel microprocessor running at 4.77 MHZ

4. had extra co-math processor

5. had memory 128KB,10MB hard disk 

6. had five 8-bit input/output channel slot.

7. supported BASICA language for programming

8. could be used for small business ,home use.

 Now-a-days, IBM computers are replaced by many new features:

1. IPS ( In-plain Display )display

2. I7 processor (2.6 GHZ)

3. NVIDIA graphics

4. 64GB memory with 1TB hard disk/SSD

5. Light weight

6. Thunderbolt support

7. Spill proof/resistant

8. Supports latest USB port

.      Examples: IBM 604, PC/XT, IBM Portable PC, etc.

2.)IBM compatible

     Features:

        

1. this is same computer as of that IBM computer. It can run all softwares as those.

2. they are low cost computers with same architecture of IBM original PC

3. used operating system ‘DOS’.

4. used firmware based BIOS

5. used BASIC programming language developed by Microsoft

6. had 8088 processor

7. used 20-bit memory space

8. used video card

9.  Spreadsheets, WYSIWYG word processors, presentation software and remote communication software. But this capability was beyond the what ‘DOS’ provided.

and many other features of original IBM computer

Computers developed by companies HP, Dell etc.,

3)Apple/Macintosh

     Features:

   

1. develops personal computer as a brand

2. a first computer which used GUI concept with Mouse

3. has different architecture than other machine

4. its first design had 64 KB to 128 KB RAM, 6809E processor

5. had 64kb of ROM with BIOS

6. had limited color display with limited resolution

7. used PASCAL and later C++ like languages for development

8. 16/32 bits operating system

9. supports multitasking,multiprogramming,real time,time sharing

10. used ‘snow white  design language’ for the computer design and look

11. owes own hardware, softwares, architectures.

12. expensive systems

Now-a-days, apple computers come with following features:

1. Retina display

2. Ultraportable

3. Primary Memory 16 GB with SSD and secondary upto 1TB (SSD or Hard disk)

4. I5 processor

5. Large screen

6. Intel graphics

7. USB

8. Multi-touch trackpad

9. Thunderbolt (40GB/s)

10. First aid button

11. Keychain (for password)

12. Secured (unix based)

13. Finger print etc

on the basis of size

 We have four computers on the basis of size.

1.Super computers

2.Mainframe computers

3.Mini computers

4.Micro computers

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Let's know in detail.

1.Super computers:

        Features:

                    

1.  A supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of calculation.

2.  Most powerful, fastest, and also very expensive.

3. performance is measured in FLOPS(FLoating-point Operations Per Second)

4.  Can perform more than 1 trillion calculations per second.

5.  Parallel processing is done in this computer. It may use symmetric or Massive parallel processing

6. uses powerful operating system (LINUX) with lightweight kernel. 

7. Supercomputers of the 21st century can use over 100,000 processors.

8. Supports more number of terminals at same time (more than 1000)

9. while working they may share memory or operating system or bus with processor.

10. A number of RISC (Reduced Instruction Set Computer) processor are used in supercomputer and its world length is 64 or more bit.

11.  use of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.

12. advanced inputs, outputs,secondary storage with primary.

100’s of GB of RAM, 1000’s of GB of secondary storage

   Examples: CRAY X-MP/24, NEC-500, PARAM, Fujitsu VP-2600/10,ANURAG.

2.Mainframe computers

        Features:

            

1. Mainframes are designed to handle very high volume of data. it can be said one housed CPU.

2. Less powerful,smaller in size and less expensive than supercomputer.

3. resulting in high reliability and security

4. measured in millions of instructions per second (MIPS)

5. word length was 32-bit or more.

6.  more number of input-output facilities with the ability to offload to separate engines.

7. supports virtualization (runs many instances in virtual environment without using physical devices)

8. supports hot swapping.

9.  supporting hundreds, or even thousands, of users/processors simultaneously.

10. supports fault tolerant .

11. mostly used for transaction processing

       Examples: z900, z990, System z9, and System z10, etc

3.Mini computers:

    Features:

            

1. It is a general purpose machine with a smaller CPU than a mainframe and super

2. It can be used as midrange servers.

3. Its word lengths are usually 16 to 32 bits.

4. It has a transfer rate of about 4 million bytes/second.

5. It supports multi-tasking,multi-programming concept

6. It had 4-bits bus system called bit-slice architecture

7. It can support all high level languages.

8. It can support between 15 to 25/50 terminals.

9. The CPU speed is 100 kips to 500 MIPS (Million Instructions per second).

10.  The main memory size ranges from 256kb to 32Mb.

Examples: MAI Basic4, DEC PDP and VAX Series, Prime Computer Prime 50, Data General Nova, Wang Laboratories 2200 and VS Series, etc.

4.Micro computers:

        Features:-

            

1. mallest and cheapest computer compared to super or mainframe or mini.

2. it is general purpose machine and does not need dedicated room.

3. contains only one microprocessor so called microcomputer.

4. supports 16/32/64 bits system.

5. used with CUI/GUI operating system.

6. used inputs like keyboard,mouse with monitor.

7. used RAM as primary memory (256Kb or more) and magnetic disk/optical disk as secondary.

8. does not support more no. of terminals.

9. its microprocessor speed is from MHZ to GHZ.

10. used for small business,accounting, for home and word related problems

11. . used intel chip like 8008

12. supports multiprogramming, multitasking, real time processing etc.

13. it has many types like, PDA,LAPTOP,TABLET ETC

         Examples of such computers are PS 386, PS 486, PENTIUM (P - I, II, III, IV), IBM PC, PC-AT, etc.

on the basis of working principle

 We have following computers on the basis of working principle/mechanism.

1)Analog computers

2)digital computers

3)Hybrid computers

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Let's know in detail.

1)Analog computers:-

                         An analog computer is a form of computer that uses the continuously changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. In contrast, digital computers represent varying quantities symbolically, as their numerical values change.

       Features:      

1. uses variable like pressure,temperature etc whose values vary continuously.

2. uses sine wave.

3. It records waveforms as they are.

4. may subject to deterioration of wave by noise.

5. more likely have low accuracy

6. hardware is not so flexible

7. best suited for audio and video transmission

8. consumes less bandwidth

9. error prone

e.g. Plesley,speedometer etc

2)digital computers:-

                    Digital computer is a computer which stores data in terms of digital numbers and proceeds in discrete steps from one state to another.

        Features:-

            

1. does not use variable concept; rather uses discrete values to represent information.

2. uses square wave (for max and min voltage)

3. waveforms are converted into numbers to record information.

4.  without deterioration during transmission 

5. high level of accuracy

6. Digital hardware is flexible

7. for any type of computing

8. consumes more bandwidth

9. mostly free from errors

                                                                picture source:theintactone.com

3)Hybrid computers:-

                    Hybrid computers are computers that exhibit features of analog computers and digital computers. The digital component normally serves as the controller and provides logical operations, while the analog component normally serves as a solver of differential equations.

        Features:-

        
It is combination of qualities analog and digital computers.

2.  It can process both continuous and discrete data.

3.  It has capability to convert one type of data to another.

4.  It is the special purpose machine.

5.  It is mostly used in airplane, hospital, weather forecasting.

6.  It usually has high cost compared to analog and digital.

Examples: HRS 100, radar, XPC 100, GVS 100.