1. PRESENTED BY – ARJUN BCA-X1 COMPUTER FUNDAMENTAL AND OFFICE AUTOMATION CFOA ASSIGNMENT-2 Submitted To: Aanchal Pathak mam Submitted By: Arjun (X3) Computer memory

2. Content What is Computer Memory? Why is memory important or needed for a computer? Types of Computer Memory Primary Memory Secondary Memory Primary Vs Secondary Memory Memory Units 2

3. 3 What is computer memory ? 1.Computer memory, device that is used to store data or programs (sequences of instructions) on a temporary or permanent basis for use in an electronic digital computer.digital computer 2.Computers represent information in binary code, written asbinary code sequences of 0s and 1s. 3.Each binary digit (or “bit”) may be stored by any physical system thatbit can be in either of two stable states, to represent 0 and 1. 4.For example, if the computer has 64k words, then this memory unit has 64 * 1024 = 65536 memory locations. The address of these locations varies from 0 to 65535.

4. Why is memory important or needed for a computer? 4 Each device in a computer operates at different speeds and computer memory gives your computer a place to quickly access data. If the CPU had to wait for a secondary storage device, like a hard disk drive, a computer would be much slower.

5. Types of Computer Memory 5

6. Memory is primarily of two types -  Primary Memory/Main Memory.  Secondary Memory. 6

7. Primary Memory/ Main Memory  This is the main memory of the computer. CPU can directly read or write on this memory. It is fixed on the motherboard of the computer.  Primary memory is further divided in two types: 1.RAM(Random Access Memory) 2.ROM(Read Only Memory) 7

8. Difference between Ram and Rom- Basic for comparisonRandom Access Memory (RAM) Read Only Memory (ROM)  Memory type o Volatile o Non-volatile  Memory capacity o 1 to 256 GB per chip o 4 to 8 MB per chip  Operation type o Read only write both o Only read  Speed o Fast o slow  Storage type o Temporary o Permanent  Also referred as o Primary memory o Secondary memory  Presence of data according to power source o The stored data in RAM lost in case of power failure o Data retained in ROM even if the power is turend off  Accessibility to proccesser o Processor can directly access the data in RAM o Processor canot directly access the data in ROM  Cast o High o low 8

9. Characteristics of Primary Memory-  These are semiconductor memories.  It is known as the main memory.  Usually volatile memory.  Data is lost in case power is switched off.  It is the working memory of the computer.  Faster than secondary memories.  A computer cannot run without the primary memory. 9

10. Secondary Memory  This memory is permanent in nature. It is used to store the different programs and the information permanently (which were temporarily stored in RAM). It holds the information till we erase it.  Different types of secondary storage devices are: 1.Hard Disc, Compact Disc, 2.DVD, Pen Drive, 3.Flash Drive, etc. 10

11. Hard Disc Drive  Hard disk drive is made up of a series of circular disks called platters arranged one over the other almost ½ inches apart around a spindle.  Disks are made of non-magnetic material like aluminum alloy and coated with 10-20 nm of magnetic material. 11

12. CD DRIVE  CD stands for Compact Disk. CDs are circular disks that use optical rays, usually lasers, to read and write data.  They are very cheap as you can get 700 MB of storage space for less than a dollar. CDs are inserted in CD drives built into CPU cabinet.  They are portable as you can eject the drive, remove the CD and carry it with you. 12

13. Pen drive  Pen drive is a portable memory device that uses solid state memory rather than magnetic fields or lasers to record data.  It uses a technology similar to RAM, except that it is nonvolatile. It is also called USB drive, key drive or flash memory. 13

14. Characteristics of Secondary Memory-  These are magnetic and optical memories.  It is known as the backup memory.  It is a non-volatile memory.  Data is permanently stored even if power is switched off.  It is used for storage of data in a computer.  Computer may run without the secondary memory.  Slower than primary memories. 14

15. Difference between Primary Memory and Secondary memory-  Primary memory  Secondary memory  Primary memory is known a  computer’s primary memory.  It is the cheapest type of memory for computers.  It is quite fast.  It is very slow in contrast to primary memory.  It is the region in a computer system where data is stored by the computer’s CPU for quick, easy and direct access, for example hard disk, etc.  It is stored on secondary storage devices such as hard drives, DVDs, CD-ROMs, and so on.  There are two kinds of primary memory namely RAM and ROM. It is temporary  In fact, it is often permanent. 15

16. MEMORY UNITS  Data in the computer’s memory is represented by the two digits 0 and 1.  These two digits are called Binary Digits or Bits.  A bit is the smallest unit of computer’s memory.  Bits=0,1 1 Byte= 8 bits(e.g,11001011)  1 KB(kilobyte) = 1024 Bytes 1 MB(megabyte) = 1024 KB 1 GB(Gigabyte) = 1024 MB 1 TB(Terabyte) = 1024 GB 16

17. 17 THANK YOU