Computer Performance & Storage Devices Computer Technology

Computer Performance

Boot Process Sequence of events that occurs between the time you turn on a computer and the time that it becomes ready to accept commands. Purposes Runs a diagnostic test to make sure everything is working. Loading the operating system, so the computer can carry out basic operations.

6 events of the boot process: Power up Start boot program Power-on self-test Identify peripheral devices Load operating system Check configuration and customization

Circuits The path from one component of a computer to another that data uses to travel. Circuits run between RAM and the microprocessor. RAM and various storage devices.

Silicon Chip Silicon is melted sand. What the circuits are embedded into to keep them together.

Speed The computer’s speed is measured by the speed of its internal clock - a device to synchronize the electric pulses. Speed is measured in units called Hertz (Hz). Instead of megahertz it is now up to gigahertz

Pentium Name of the CPU. Pentium is the 5th generation of the Intel processor. Other generations were called

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.

The Computer’s Memory RAM (random access memory): –is the most common type of primary storage, or computer memory –is used to store program instructions and data temporarily –can quickly retrieve information –will not remain if power goes off (volatile)

The Computer’s Memory ROM (read-only memory): –information is stored permanently on a chip. –contains startup instructions and other permanent data.

Store Information Memory and storage devices are used to store information Primary storage is the computer’s main memory Secondary storage uses disks or other media

Buses, Ports, and Peripherals Slots and ports also allow external devices called peripherals to be added to the system (keyboard, monitor, and mouse). Without peripherals, the CPU and memory are like a brain without a body.

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.

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

Storage Devices Used to keep data when the power to the computer is turned off. Medium/media Location where data is stored.

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

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.

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

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.

Zip Disk Floppy disk technology manufactured by Iomega. Available in 100 MB and 250 MB versions.

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.

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

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.

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.

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.

Resources Parsons, June Jamrich, and Dan Oja. Computer Concepts. Boston: Course Technology - Thompson Learning, 2002.