1. U ‐ Data Recovery Glossary
Ultra SCSI– Provides 20 MB/s transfers over an 8‐bit bus or 40 MB/s transfers over a
16‐bit Wide SCSI bus. This feature is usually found in SCSI‐3 drivers and is also known
as Fast‐20 SCSI.
Ultra DMA/33– A high‐speed host data transfer feature that transfers data at 33.3
MB per second.
Uncorrectable Error– An error that cannot be overcome using Error Detection and
Correction.
Unformatted Capacity – The total number of usable bytes on a disk.It includes the
space that is required to boundary definitions, record location, and servo data. (See
also formatted capacity.)
Unrecoverable Error – A read error that cannot be overcome by an ECC scheme or
by rereading the data when host retries are enabled.
Untagged Queuing– The ability of the drive to receive, from each initiator, a
maximum of one I/O process.
Unzip‐ To extract (see extract) a Zip archive.
Upgrade – The replacement of a hard drive with one offering greater capacity or
performance, or both.
Ultra ATA/100 – Ultra ATA/100 or Ultra DMA/100 is an extension of the current
Ultra ATA/66 interface. This new high‐speed interface has the capability of 100
Mbytes/sec transfer rate and maximized disk performance under the current PCI
local bus environment.
UUencode‐ The basic unit of information – a byte – comprises of 8 on/off signals.
Many file formats are 8 bit or binary. Uuencode helps to convert 8 bit data to 7 bit
data which is required for Email which is a 7 bit medium. It accomplishes this by
creating a single stream by joining all file bits together and then diving the stream in
chunks of 7 bits. The emailed data must eventually be Uudecoded at the receiving
end.
Dolphin Data Lab http://www.dolphindatalab.com/