Digital Storage & Operating system

DIGITAL STORAGE

Definition: A physical material that keeps information, and applications in computer.

• Capacity; quantity of bytes that storage medium can hold (Yottabyte (YB), 1 septillion)
• When you turn off the computer/mobile device, contents of storage remain intact
• Duration of a storage device to locate item on a storage medium is known as access time
• The faster transfer rate is goes to Memory (most RAM), interpreted and executed by the processor

Type of Storage

Storage refers to :

·         SSDs; Solid State Drive (flash memory chips) ,  no moving part (smaller capacity) with higher price (1TB , RM 1000) and high speed, but short lifespan and low power consumption (2W) if compared to hard disk

·         Hard disks; inflexible circular platters (magnetic particles), that store data and instructions

* A head crash, a read/write head touches the surface of platters (keep backup of hard disk)

* External hard disk, separate freestanding storage device, connect with cable

·         USB Flash Drives; plug into USB port

·         Memory Cards; removable flash memory, that can be inserted and removed from slot in a device

·         Optical Discs; portable disc, that is written and read by a laser

It stores items in single track that spiral from the center to the edge

CD-ROM – only can be read (single-session)

CD-R – can be only written once

CD-RW – erasable (rewritable) multisession disc

DVD is same goes to CD but with higher capacity

·         Cloud Storage; another online storage media option provided by Internet Service

Others:

• Magnetic stripe card
• Smart card
• Radio Frequency Identification (RFID), contains the information to be transmitted via radio waves

·         Microfilm and microfiche, stores microscopic images, in roll/sheet film

OPERATING SYSTEM
Definition

A set of programs including instructions that work together to coordinate all the activities among computer and mobile device hardware

Functions

- A user interface (UI) controls how you enter data and instructions 

- Manage programs: directly affects our productivity

1.           single and multi-task
2.           foreground and background
3.           single and multi-user 

- Determine the order in which tasks are processed

DRIVE: a small program that tells the operating system how to communicate with the certain device

- Establish an internet connection

- Start and shut down the computer or mobile device

- Provide the tools to manage the computer/device/programs

1.           screen saver
2.           file compression
3.           search
4.           file manager
5.           backup and restore

- Update operating system software: play automatically configures new devices as we install and provide new features to the program

- Enable us to login/access resources on network

USERNAME: user ID, a spesific users                  PASSWORD: a private of combination of characters

Example of Operating System (OS) by category

Desktop ; Windows, OS X, UNIX, Linux, Chrome OS
- It works on desktop, tablet, laptop
- Windows 8 comes with unique features, include desktop interface
- It eases the users to make some input/function within touch of keyboard
- OS X is the latest version
- UNIX , multitask OS develope in early 1970's
- Linux, multitask UNIX-based OS

Mobile ; Google Android, Apple iOS, Windows Phone
- It resides on firmware
- Android, an open source, Linux-based mobile OS designed by Google
- iOS, specifically for Apple's mobile devices that developed by Apple
- Windows phone, runs on smartphones that developed by Microsoft