SCSI-2


Also found in: Acronyms.

SCSI-2

(hardware)
A version of the SCSI command specification.

SCSI-2 shares the original SCSI's asynchronous and synchronous modes and adds a "Fast SCSI" mode (<10MB/s) and "Wide SCSI" (16 bit, <20MB/s or rarely 32 bit).

Another major enhancement was the definition of command sets for different device classes. SCSI-1 was rather minimalistic in this respect which led to various incompatibilities especially for devices other than hard-disks. SCSI-2 addresses that problem. allowing scanners, hard disk drives, CD-ROM drives, tapes and many other devices to be connected.

Normal SCSI-2 equipment (not wide or differential) can be connected to a SCSI-1 bus and vice versa.
References in periodicals archive ?
Technology enhancements further evolved SCSI-2 devices by using active and forced perfect termination (FPT) methods.
SCSI-2 Same as SCSI, but with a50-pin connector instead of a 25-pin connector to support multiple devices Wide SCSI Uses a wider cable (168 cable lines to 68 pins) supporting 16-bit transfers Fast SCSI 8-bit bus, but doubles the clock rate supporting data rates of 10 MBps Fast Wide 16-bit bus supporting data rates of 20 MBps SCSI Ultra SCSI 8-bit bus supporting data rate of 20 MBps SCSI 3 16-bit bus supporting data rates of 40 MBps.
Another possibility for use with a parallel port is the SCSI-2 adapter, for which two speeds are available.
Many computer devices are available on these cards, such as hard drives (over 100 megabytes (MB) on a Type III card), modems (Type II cards), various types of memory (e.g., random access memory (RAM), ROM and flash memory), local area network connectors and SCSI-2 interfaces (Type II cards).
Some notebook manufacturers offer SCSI-2 ports on their machines, others offer built-in CD-ROM drives and still others offer a docking station (a box in which a notebook PC sits in and plugs into to provide a driect hookup to the motherboard (and motherboard slots)).
Sometimes the term "SCSI-2" is used to identify the 50 pin high density connector that was also introduced in the SCSI-2 specifications.
A: SCSI-2 is available Global Engineering or the draft copy on the SCSI committee (T10) web site: www.t10.org.
The industry understood SCSI-2 and SCSI-3, but when the T10 committee went to Fast-20 and then to SPI-2, everyone was at a loss as to what to call SCSI devices that supported those standards.
The mixing of SCSI-2, SCSI-3, or Ultra SCSI devices with Ultra2, Ultra3/Ultra160 (or higher) SCSI devices is allowed and it will work if the Ultra2 and higher SCSI devices have MSE (Multi-mode Single Ended) drivers.
[TABULAR DATA NOT REPRODUCIBLE IN ASCII] STA/T10 SCSI TERMINOLOGY CROSS-REFERENCE Marketing Standards Original Max Bus Bus Terms Terms Standard Speed Width (MB/Sec) (Bits) SCSI 1, SCSI-2 Fast-5 SCSI, SCSI-2 5 8 Fast SCSI Fast-10 SCSI-2 10 8 Fast SCSI Fast-lO SCSI-3 (SPI, SIP) 10 8 Fast Wide SCSI Fast-lO SCSI-3 (SPI, SIP) 20 16 Ultra SCSI Fast-20 F-20 20 8 Ultra SCSI Fast-20 F-20 20 8 Wide Ultra SCSI Fast-20 F-20 40 16 Wide Ultra SCSI Fast-20 F-20 40 16 Wide Ultra SCSI Fast-20 F-20 40 16 Ultra2 SCSI Fast-40 SPI-2 40 8 Wide Ultra2 SCSI Fast-40 SPI-2 80 16 Wide Ultra3 SCSI Fast-80 SPI-3 160 16 Ultra 160 SCSI [*] Fast-80 SPI-3 160 16 Ultra 320 SCSI [**] Fast-160 SPI-4 [***] 320 16 Marketing Max.
Where did half of the connectors go between the SCSI-2 and SCSI-1 connectors?
Some of the new features incorporated into SCSI-2 include wide SCSI with data transfer at bus widths of 16 and 32-bits.