Main memory of computer .ppt

Main memory of computer .ppt

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  What is MainMemory? • Main Memory is an internal storage area in a computer, which is availed to store data and programs either permanently or temporarily. • Computer memory is any physical device capable of storing information temporarily, like RAM (random access memory), or permanently, like ROM (read-only memory). • Memory devices utilize integrated circuits and are used by operating systems, software, and hardware.
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  Why is memoryimportant or needed for a computer? • 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.
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  Types of ComputerMemory • Computer memory is broadly divided into two groups and they are: 1. Primary memory 2. Secondary memory • When the main memory holds instructions and data when a program is executing, the auxiliary memory or secondary memory holds data and programs which are not currently in use and furnishes long term storage.
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  Types of ComputerMemory
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  1. Primary 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 the only type of memory which is directly accessed by the CPU. The CPU continuously reads instructions stored in the primary memory and executes them. • Any data that has to be operated by the CPU is also stored. The information is transferred to various locations through the BUS.
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  1. Primary Memory •Primary memories are of two types. They are: i. RAM (Random Access Memory) ii. ROM (Read Only Memory)
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  2. Secondary Memory •Secondary memory or auxiliary memory consists of slower and less expensive device that communicates indirectly with CPU via main memory. • The secondary memory stores the data and keeps it even when the power fails. It is used to store or save large data or programs or other information. • 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.
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  2. Secondary Memory •Different types of secondary storage devices are: Hard Disc Compact Disc DVD Pen Drive Flash Drive Magnetic disks Magnetic tape Optical disk Mass storage devices USB
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  Memory Units • Datain 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. i. Bits = 0,1 ii. 1 nibble = 4 bits iii. 1 Byte = 8 bits (e.g,11001011) iv. 1 KB(kilobyte) = 1024 Bytes v. 1 MB(megabyte) = 1024 KB vi. 1 GB(Gigabyte) = 1024 MB vii. 1 TB(Terabyte) = 1024 GB
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  Memory Units