Skip to main content

Secondary Storage Devices

Secondary Storage Devices


Secondary storage (also known as external memory or auxiliary storage) differs from main memory in that it is not directly accessible by the CPU. The secondary storage devices hold data even when the computer is switched off. An example of such a device is the hard disk.


The computer usually uses its input/output channels to access data from the secondary storage devices to transfer the data to an intermediate area in the main memory. Secondary storage devices are non-volatile in nature, cheaper than the primary memory, and thus can be used to store huge amounts of data. While the CPU can read the data stored in the main memory in nanoseconds, the data from the secondary storage devices can be accessed in milliseconds.


The secondary storage devices are basically formatted according to a file system that organizes the data into files and directories. The file system also provides additional information to describe the owner of a certain file, the access time, the access permissions, and other information.


Some of the secondary storage devices are magnetic tape, hard disks, compact disks, USB flash drive, memory card, and blue-ray disc.

Comments

Popular posts from this blog

Cache Memory

Cache Memory Cache memory is an intermediate form of storage between registers and the primary memory. It is used to store instructions and data that are repeatedly required to execute programs thereby improving the overall system speed and increase the performance of the computer. Keeping frequently accessed data and instructions in the cache avoids accessing the slower primary memory. Working of the Cache Memory When a program is being executed and the CPU wants to read data or instructions, then the following steps will be performed: CPU first checks whether the data or instruction is available in cache memory. If it is not present, the CPU reads the data or instructions from the main memory into the processor registers. The CPU also copies it into the cache memory. When the same piece of data/instruction is needed, the CPU reads it from the cache memory instead of the main memory

Generation Of Computers Explain

  Generation Of Computers Generation of computers  can be understood by looking into five generations. With each new generation of computers, there had been advancement in computer technology. The circuitry became smaller with enhanced speed, less consumption of power, and efficient memory Therefore, each generation of computer is characterized by a major technological development that has drastically changed the way in which computers operate First Generation (1942-1955) Hardware Technology-  First generation computers  were manufactured using thousands of vacuum tubes Software Technology-  Programming was done in machine language or assembly language. Used for - Scientific application Exmaples  - ENIAC,EDVAC,EDSAC,UNIVAC I,IBM 701 Highlights They were the fastest calculating device of those times. Computers were too bulky and required a complete roomm for storage. Highly unreliable as vacuum tubes emitted a large amount of heat and burnt frequently. Requi...

Classification of computers software

CLASSIFICATION OF COMPUTER SOFTWARE Computer software is written by programmers using a programming language. The programmer writes a set of instructions (program) using a specific programming language. Such programs are known as the source code. Another computer program called a compiler is then used on the source code, to transform the instructions into a language that the computer can understand. The result is an executable computer program, which is another name for software. Examples of computer software include the following: Driver software, which allows a computer to interact with hardware devices such as printers, scanners, and video cards. Educational software, which includes programs and games that help in teaching and providing drills to help memorize facts. Educational software can be used in diverse areas, from teaching computer-related activities like typing to subjects like chemistry. Media players and media development software, which are specifically designed to play ...