Devices

Storage Devices
How a computer stores information
1. The computer stores information as a string of zeros (0) and ones (1)
The standard string length is eight O'sor 1's in a row
This standard length is called a byte
A byte equals one character
• A character is a letter, number, or symbol - it is about any thing that can be typed on a keyboard
• There are 256 standard characters used by almost all computers
2. Information size measurements
Kilobyte (KB)
• One kilobyte equals about 1024 bytes
• 1KB is about 140 words, about a half page of typed double-spaced text (words only)
Megabyte (ME)
• One megabyte equals about 1000 KB
• One megabyte equals about 1,000,000 bytes
• One megabyte equals about 500 pages of text, or one large book
Gigabyte (GB)
• One gigabyte equals about 1000 MB
• One gigabyte equals about 1,000,000 KB
• One gigabyte equals about 1•0..00,000,000 bytes
• One gigabyte equals over 1,000 books of text
â–º Some Common Storage Devices
Hard Drive
The hard drive is the primary device that a computer uses to store information. The hard drive stores programs, data files, saves files, and organizes files. The hard drive is located inside the computer case. The hard drive, magnetically stores data on stacks of rotating disks called platters.
Floppy Drive
The floppy drive stores and retrieves information on a floppy disk
CD -ROM Drive
CD-ROM is a device that reads information stored on a compact disc. CD-ROM stands for Compact Disc Read Only Memory. One CD is equal to the space in over 40 floppy disc.
Removable Hard Disk.
A zip disk is a removable disk that holds a large amount of information. A zip disk can be used to achieve, protect and transfer large amounts of data.
Communications Devices
Specific equipment and programs are needed to connect to the Internet or to communicate with other computers. You can use any type of computer such as IBM compatible or Macintosh to connect to the Internet or communicate with other computers. You need special programs to use the Internet. Most companies that connect you to the Internet provide the programs you need free of charge. You also need a modem to connect to the Internet. A modem translates computer information into a:"formthat can be transmitted over telephone lines. Modems can be used to connect you to the Internet, exchange information, and to send and receive faxes.
Peripheral Devices
A peripheral devices is any piece of hardware attached to a computer. A few examples of peripheral devices are printers, scanners, and digital cameras.