Computer Storage UNIT-6 Notes PDF

# COMPUTATIONAL & I.T. ## UNIT 6: COMPUTER STORAGE ### DATA STORAGE AND RETRIEVAL METHODS - **Data Storage**: Refers to saving data in a specific medium for future use. It involves both primary and secondary storage devices. - **Data Retrieval**: The process of accessing stored data for processing...

# COMPUTATIONAL & I.T. ## UNIT 6: COMPUTER STORAGE ### DATA STORAGE AND RETRIEVAL METHODS - **Data Storage**: Refers to saving data in a specific medium for future use. It involves both primary and secondary storage devices. - **Data Retrieval**: The process of accessing stored data for processing or use. - Methods include sequential access (used in magnetic tapes) and random access (used in RAM and hard disks). ### PRIMARY STORAGE - Fast, volatile memory directly accessible by CPU. It is used for temporary data storage during processing. - **RAM (RANDOM ACCESS MEMORY):** - Volatile memory (data lost when power is off). - Used for temporary storage during execution of programs. - **ROM (READ ONLY MEMORY):** - Non volatile memory. - Stores firmware and instructions needed for the computer's basic operation. - **PROM (Programmable ROM):** - Can be written only once using a special device. - Used in embedded systems and hardware customization. - **EPROM (Erasable Programmable ROM):** - Can be erased using ultraviolet light and reprogrammable. - Useful for testing and debugging. - **EEPROM (Electrically Erasable Programmable ROM):** - Can be erased and rewritten using electrical signals. - Used in BIOSes and modern embedded systems. ### SECONDARY STORAGE - Non-volatile memory used for long-term data storage. - **Magnetic Tapes:** - Sequential access storage medium. - Used for backup and archival purposes. - **Magnetic Disks:** - Consists of a rotating disk coated with magnetic material. - Examples: Hard drives, floppy disks. - **Cartridge Tapes:** - A compact version of magnetic tapes. - Used in data backups for servers. - **HARD DISKS:** - Magnetic disk with large storage capacity. - Support random access, making them faster than tapes. - **FLOPPY DISKS:** - Portable, magnetic storage with small capacity. - Mostly obsolete now. - **OPTICAL DISKS:** - Use laser technology to read/write. - Examples: CDs, DVDs. - **Compact Disks (CDs):** - Optical disks used for storing music, software, or data. - Available in CD-ROM (read-only) and CD-RW (rewritable) versions. - **ZIP DRIVE:** - Portable magnetic disk storage with higher capacity than floppy disks. - Used for backups in the past. - **Flash Drives:** - Portable solid-state devices. - Use USB interfaces for connectivity. - **SOLID STATE DRIVES (SSDs):** - Use flash memory with no moving parts. - Faster and more reliable than traditional hard drives.