M. Guymon Pleasant Grove High School Spring 2003 RAM vs. ROM RAM “Random Access Memory” The ability of a storage device to go directly to a specific storage location without having to search sequentially from a beginning location. Very volatile Cannot hold data when the power is off. Looses all data when power is lost. ROM “Read only memory” Drives can read data from disks, but cannot store new data on them. One or more integrated circuits that contain permanent instructions that the computer uses during the boot process.

M. Guymon Pleasant Grove High School Spring 2003 Binary Number System A method for representing letters or numbers using only two digits, 0 and 1. Bit Each 0 or 1 Byte 8 bits Also referred to as Base 2 Binary Code.

M. Guymon Pleasant Grove High School Spring 2003 Memory Measurements Bit Each 0 or 1 Byte 8 bits Kilobyte Approximately 1,000 bytes Exactly 1,024 bytes Megabyte Approximately 1 million bytes Exactly 1,048,576 bytes Gigabyte Approximately 1 billion bytes Terabyte Approximately 1 trillion bytes

M. Guymon Pleasant Grove High School Spring 2003 Storage Devices Used to keep data when the power to the computer is turned off. Medium/media Location where data is stored.

M. Guymon Pleasant Grove High School Spring 2003 Hard Disk Usually mounted inside the computer’s system unit. Can store billions of characters of data. Stated in forms of bytes: Megabytes or Gigabytes

M. Guymon Pleasant Grove High School Spring 2003 Magnetic Storage Recording of data onto disks or tape by magnetizing particles of an oxide based surface coating. A fairly permanent type of storage that can be modified.

M. Guymon Pleasant Grove High School Spring 2003 Floppy Disk Round piece of flexible Mylar plastic covered with a thin layer of magnetic oxide and sealed inside a protective covering. May be referred to as a “floppy” 3½ disk capacity is 1.44 MB or 1,440,000 bytes

M. Guymon Pleasant Grove High School Spring 2003 Floppy Disk Options Formatted Preparing the disk for use by the computer. Write-protected Setting the disk so that it can not be written to by the computer.

M. Guymon Pleasant Grove High School Spring 2003 Zip Disk Floppy disk technology manufactured by Iomega. Available in 100 MB and 250 MB versions

M. Guymon Pleasant Grove High School Spring 2003 Digital Audio Tape Method of storing large amounts of data on tape using helical scan technology to write data at high densities across the tape at an angle.

M. Guymon Pleasant Grove High School Spring 2003 Optical Storage Means of recording data as light and dark spots on CD or DVD. Reading is done through a low-power laser light. Pits Dark spots Lands Lighter, non-spotted surface areas

M. Guymon Pleasant Grove High School Spring 2003 CD-ROM “CD – Read Only Memory” Also called CD-R CD-Read Storage device that uses laser technology to read data that is permanently stored on compact disks, cannot be used to write data to a disk.

M. Guymon Pleasant Grove High School Spring 2003 CD-RW “CD-Read Write” A storage device that reads data from CD’s and also can write data to CD’s. Similar to a CD-ROM, but has the ability to write to CD.

M. Guymon Pleasant Grove High School Spring 2003 DVD-ROM “Digital Video Disks – Read Only Memory” Reads data from CD’s (audio and data) and DVD’s (data or movie) Cannot be used to write data to a disk.

M. Guymon Pleasant Grove High School Spring 2003 Resources Parsons, June Jamrich, and Dan Oja. Computer Concepts. Boston: Course Technology - Thompson Learning, 2002.