SCSI


Also found in: Dictionary, Thesaurus, Medical, Financial, Acronyms, Wikipedia.

SCSI

[′skəz·ē]
(computer science)

SCSI

SCSI

(Small Computer System Interface) Pronounced "scuzzy," SCSI is an earlier hardware interface for up to 15 peripherals connected to one expansion card, called a "SCSI host adapter." Introduced in 1986 by Shugart Associates (see SASI), this parallel architecture was replaced by its serial successor (see serial attached SCSI).

SCSI hard drives were used in mainframes, servers and storage arrays in the late 1980s and 1990s because they were very robust. Initially the only kind chosen for multi-drive RAID configurations, less-costly IDE drives were eventually used (see RAID, IDE and SATA).

SCSI Was a Mini-Network
The SCSI bus connects up to 15 devices in a daisy chain topology, and any two can communicate at one time: host-to-peripheral and peripheral-to-peripheral. For more details, see SCSI Architecture Model, SCSI signaling, SCSI connectors and SCSI switch.


A "Scuzzy" Daisy Chain
SCSI enabled multiple peripherals to take up only one expansion slot in the computer.







SCSI Ports
To enable the daisy chain, all SCSI devices had one "in" and one "out" port plus a dial to set the device number. These SCSI-1 sockets are on the back of a 1990s disk drive. See SCSI connectors.
References in periodicals archive ?
If this is not convincing enough, SCSI LTO 3 drives have Ultra320 SCSI ports capable of 320 MB/sec.
New features will include native command queuing, an external interface (to allow the use of external enclosures), a port multiplier to further decrease cable clutter and hot-swap capability--features that up until now were only available in a SCSI environment.
With a properly installed SCSI adapter card in a PC expansion slot (an internal plug designed to accommodate added peripherals), a user can connect up to seven peripherals.
Over the next year, almost all server manufacturers will launch servers that are built entirely on serial attached SCSI technology.
Ultra640 uses paced data transfers or packetized SCSI; a free running clock; ISI precompensation drivers and active adapter filter receivers; skew compensation; training patterns for the adaptive active filters; and expander communications.
The SXP 36x3G and SXP 24x3G SAS expanders offer increased system performance, higher capacity, scalability and lower bill of material costs with an embedded MIPS-Powered storage enclosure processor, complete with a SCSI Enclosure Services (SES) software development kit (SDK).
Title:The book of SCSI - 2nd edition Author:Gary Field, Peter Ridge Published by: No Starch Press ISBN:1-886411-10-7 Price:USD49.95 Reviewer:Caroline Turner
Ultra160 SCSI fills these needs with its high performance characteristics, its reliability, and its compatibility that protects user's current and future investment.
At the high-end, the biggest challenge to SCSI is likely to come from fibre channel at the high-end, especially for long distance connections and complex storage area networks where switches and routers are required.
Distance limitations that have often plagued SCSI are resolved by cascading switches or through remote fiber connections up to 20 km.
Many current systems employ Ultra 320 parallel SCSI for boot drives, local data storage, or external arrays of modest size.
Scuzzy refers to the small computer system Interface (SCSI).