Chapter 8

Hard Disk Drive

Memory

Storage

ROM

History(Background)

Is currently used in almost every
electrical device and have advanced very far compared to the technological developments of the previous century.

The first storage device capable of storing up to1Gigabyte or 1000 Megabytes of data was made by IBM [International Business Machines], who were also responsible for many early storage devices

When computer storage had started gaining "relevance" new methods of storage were constantly being used

Punch cards

Punched Tape

Magnetic Drum Rolls

Types

Primary

Offline storage refers to any storage medium that must be physically inserted into a system every time a users wants to access or edit data. Offline storage can be any type of internal or external storage that can easily be removed from the computer. Offline storage is also known as removable storage.

also known as main storage or memory, is the area in a computer in which data is stored for quick access by the computer's processor

RAM (random access memory) is the place in a computing device where the operating system (OS), application programs and data in current use are kept so they can be quickly reached by the device's processor. RAM is used in general purpose computers and embedded computers like in calculators

RAM is synonymous
with Primary Memory

ROM(Read Only Memory) is "built-in" computer memory containing data that normally can only be read, not written to. ROM contains the programming that allows your computer to be "booted up" or regenerated each time you turn it on. Unlike a computer's random access memory (RAM), the data in ROM is not lost when the computer power is turned off. The ROM is sustained by a small long-life battery in your computer.

ROM is also primary memory

Embedded devices: use software for ROM called firmware

General purpose computers: use bootstrap which is a set of instructions to determine the type of basic hardware of the computer and for finding and loading the OS (Operating System)

Another rewritable type of ROM is EPROM or Erasable Programmable Read Only Memory

Used for devices that have to Upgrade their firmware in the future

Rewriting and erasing data to ROM is called Flashing

Secondary

Magnetic Storage is the manipulation of magnetic fields on a medium in order to record audio, video or other data.Magnetic storage has been around in many forms since 1888 by Oberlan Smith, who publicized his audio recording on a wire in Electrical World. In broad terms, magnetic storage mostly works very similarly to Smith's recording. Read and write heads (either combined or separate) are used to align the magnetic fields on the recording medium. A great variety of analog and digital devices using magnetic storage.Many types of magnetic storage involve a tape medium ether on a real or in a cassette that is moved by read and write heads. Similar working devices include real to real tapes, 8 track tapes and audio cassettes as well as video storage mediums of VHS, D-VHS and Betamax.In main computer storage mechanisms have generally involved a spinning disc or platter and read write heads on an armature (though there have also been tape drives and magnetic drums used in the past). Disk storage solutions include floppy drives (8, 2.5 and 5.25 inch alike), magneto-optical rewritable discs as well as hard drives including helium hard drives. These technologies have taken us from capacities of kilobytes to numerous terabytes and bytes per second to 100+ MB per second. Laser switched magnetic storage hard drives have promised to improve performance by 1000 times in the future.

Hard Disk Drive

Optical storage is the storage of data on an optically readable medium. Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning optical disc. this includes CD, BLU-RAY, DVD and the Blu-ray and DVDs can have multiple layers to accommodate more storage

Solid-state storage (SSS) is an increasingly popular backup alternative to traditional storage technologies such as the hard disk drive (HDD), compact disc, rewriteable (CD-RW), and digital versatile disc RAM (DVD-RAM).All SSS devices, also called solid-state drives (SSDs), function entirely by electronic means, and therefore they lack internal moving parts. In theory, this characteristic should allow SSS devices to perform faster, longer, and more reliably than devices that employ mechanical components. In practice, the situation is more complex because optimum performance requires dovetailing of the underlying technologies.

A flash drive is a small offline, ultra-portable storage device which, unlike an optical drive or a traditional hard drive, has no moving parts.Flash drives connect to computers and other devices via a built-in USB Type-A plug, making a flash drive a kind of combination USB device and cable.Flash drives are often referred to as pen drives, thumb drives, or jump drives. The terms USB drive and solid state drive (SSD) are also sometimes used but most of the time those refer to larger and not-so-mobile USB-based storage devices.