Lesson No: 4 Classification of Computer, Language Memory CHBT-01 Basic Micro process & Computer Operation Lesson No: 4 Classification of Computer, Language Memory

Classi. of Computer, Memory & Computer Language Classification of Computer Analog Digital Super Mainframe MINI Micro PC/AT PC/XT PC - 286 - 386 - 486 - 586(Pentium I,II,III,IV Speed Increase

Classi. of Computer, Memory & Computer Language Types of Memory Internal/Primary External/Secondary Floppy Disk RAM -Volatile ROM -Non Volatile Compact Disk Hard Disk -RAM : Random Access Memory -ROM : Read Only Memory CD-R CD-R/W

Classi. of Computer, Memory & Computer Language Low Level Language High Level language - C,COBOL Assembly Language Machine Level Alpha Numeric Symbol used Binary Digit ( only 0 , 1 used)

Primary Memory It is the main memory of computer. This memory is used to execute all primary works. This memory is further classified as Internal memory and External memory. Primary internal memory is CPU’s M.U. whereas primary external memories are RAM and ROM. RAM:- This is a Random Access Memory. Speed of computer is greatly depends on this memory. All programs are loaded in to this memory first. When the computer is switched off, the data in this memory is erased completely. It is known as “ Read/Write or volatile Memory”.

Primary Memory ROM:- This is a Read Only Memory. Data stored in this type of memory can be read only. It can not be altered in usual manner. Manufacturer stores basic data regarding pre-installed hardware on to it. It is fitted on the motherboard.

Secondary Memory Computer needs extra amount of memory to store large amount of data permanently. Secondary memory of different types are used for this purpose. They are as follows; Floppy Disk:- This device is not so popular today due to its limited storage capacity. It can store up to 1.44 Mb of data. Earlier 1.2 Mb floppy was also used. It can be read or right with the help of floppy disk drive. It is a portable device used to store and transfer small amount of data from one computer to another.

Secondary Memory Hard Disk:- This is the main storage device of computer. It can store very large amount of data permanently. It remains fixed in computer since it is called “ Fixed Disk” also. All software is stored in this disk. Data is stored on carefully sealed diskette, which may vary in numbers.

Hard disk construction Construction of Hard disk is shown in fig. in which different arms shown. They are operated by head stack assembly. Diskettes are placed on a common spindle which runs at 3600 to 7200 R.P.M. It can be of IDE type or latest SATA type technology.

CD-Rom (Compact Disk Read Only Memory):- This is a optical media with significant use today. It is a portable media which can store up to 750 Mb of data. Sound/picture/ data files can easily stored on this media. Once data written on this device can not be altered. It can play media file of 72 to 80 minutes. It is very popular device to distribute different software and multimedia files. It is cheaper than the other media. CD-RW can be erased and used frequently.

DVD (Digital Versatile Disk):- Develop-ment is made on optical media which resulted in DVD. This media can store vast amount of data i.e. 4.7 Gb to 8 Gb. It is becoming more popular than CD-Rom now-a-days. DVD writer is used to write data on it. Flash Drive:- This is another prevailing in storage media. It is also known as Pen drive or Flash drive or storage stick. Overwhelming effect of this media is due to ease of its use. A tiny piece of this media can store large amount of data, i.e. 1 to 8 Gb. It is plugged to USB port of Computer.