BIOS - Stands for Basic Input/Output System. The BIOS runs at the startup sequence where it configures devices and then boots the operating system. The function of the BIOS is so vital that the information on the BIOS is stored on a ROM chip separate from the hard drive to protect it from potential crashes.
Winchester disks - This is a former code name for an early IBM hard disk model that is sometimes still used to refer to hard drives in general.
For more information on RAID read our RAID recovery & Learn more about RAID pages
Spindle - The drive's center shaft, used to mount hard disk platters.
Bad block - A bad block is the result of a media flaw or damaged format markings which causes the data held on a block (usually the size of a sector) to be unreliable.
First conceived in 1987 by a group of Berkeley researchers, five levels of RAID were defined and three of which (Levels 1, 3 and 5) have been found to be commercially viable. Each level offers a different way of distributing data across an array of disks so that the failure of a single disc does not cause data loss. There is also a variant of RAID known as level 0 (see Striping).
Operating System - The operating system is programmed to act as an interface between the user of a computer and the computer devices. This program enables the user to operate all software applications and to conveniently access all resources available on the computer including the CPU, media drives, memory, printers and storage devices.
Average seek time - This term refers to the average time required for the read/write head to move to a specific location on the media. In computing the average seek time, the time it takes to complete a larger number of random seeks is divided by the number of seeks performed.
Bit - The common abbreviation for binary digit code. A Binary digit has values of either 1 or 0 (logic 1 or logic 0 binary settings). These values or settings determine the make up of a byte of data.
CDR - Stands for re-writable compact disk (CD). Media can be written and erased on average 1000 times before malfunction. Up to 500MB can be stored on the standard 74 minute CD-74.
Level 3 and Level 5 combine the stripping technique with parity codes, enabling the recovery of data if a disk fails. Both of these levels utilize total disk capacity more efficiently than level 1.
MTBF - This refers to the mean time between failures. It is the reliability rating indicating the expected failure rate of a product in power on hours.
Megabyte (MB) - A unit of measurement equal to 1 million bytes or 1,024 kilobytes or 1,048,576 bytes
Partitioning - The purpose of partitioning is to create a logical file structure for the operating system to access and to divide a portion of the disk drive to be used by more than one disk operating system. Large disk drives can be divided into areas for the file allocation table (FAT) to access when in use.
Terabyte - Terabyte = 1,099,511,627,776 bytes (or approximately one trillion bytes). A terabyte is equivalent to 1,000 gigabytes or 1,000,000 megabytes.
