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