ITGS - Ch 2
Source: Information Technology in a Global Society by Stuart Gray
The tangible, physical parts of the computer which work together to input, process, store and output data.
- Supercomputers -*High processing speeds through Multiprocessing
- Supercomputing Super Powers (BBC) provides a graphical breakdown of the fastest supercomputers by speed, country, and operating system. Click the image below to explore these Supercomputers.
- Desktop computers - *Home theatre PCs
- Laptop computers
- Personal Digital Assistants (PDA) - Check out Pocket marvels: 40 years of hand held computers. Compiled by Computer World
- Smart Phones
- Embedded systems
Staying in Sync
•Keyboards/concept keyboards/soft keyboards
•Magnetic stripe readers
•Optical Mark recognition
•Magnetic ink character recognition
•Sensors and probes
•Radio frequency identification (RFID)
Concerns about RFID
Input Devices of the Future?
•Primary storage-High speed, electronic memory.
-Random access memory - Temporary (volatile) storage for programs and data being used in the moment.
–Read only memory - Storage that cannot be changed. Contains the computer's BIOS which tells the computer how to boot up.
•Secondary storage - Stores data and programs installed on a computer system.
–Magnetic tapes -Often used for back up but show to access because the data is sequential.
–Magnetic disks -Your hard drive. High capacity, high speed
–Flash memory - * See "Common Mistake" note on page 34
Hard Disk Security & Privacy
What happens to data stored on computers that are lost, stolen, thrown away or recycled? How can you ensure your data is safe or properly erased? (See page 35)
Watch Ghana: Digital Dumping Ground shows what can be found on the hard drives of recycled computers.
Storing Data: Bits and Bytes
All data on your computer is stored as zeros and ones or bits. Those bits are then grouped together into more meaningful units called bytes.
ASCII - American Standard Code for Information Interchange. A standard coding scheme for representing the English alphabet.
Unicode - Modern coding scheme which uses up to 4 bytes to represent each character, allowing many thousands of characters. Used to include non-English alphabets.
Plane Text - Specifies the characters that make up a text but do not include ways to specify other formatting attributes such as the font type, size, bold, underline, and color. ASCII and Unicode are examples of plain text.
Graphics Standards - Computer graphics are represented as bit and bytes like other computer data. Typically each pixel in an image uses three bytes of store space - one byte for red, one for green and one for blue.
Ports & Connectors
Designed to keep a system running if the primary system fails due to hardware or power failure.
RAID - Redundant Array of Independent Disks. Uses multiple hard disks, connected together to create a fault tolerant system.
UPS - Uninterruptible Power Supply. Provides power in case of an electricity failure.