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What is SCSI Small Computer System Interface ?

What is SCSI Small Computer System Interface ?



Small Computer System Interface (  English: Small Computer System Interface; abbreviated: SCSI)  ,   an independent processor standard for system-level interfaces between computers and smart devices (hard disks  ,   floppy drives  ,   optical drives  ,   printers  ,   scanners  ,   etc.).


It is an intelligent general-purpose interface standard that has the ability to communicate with many types of peripherals. SCSI uses the standard software interface of ASPI (Advanced SCSI Programming Interface) to enable the drive to communicate with the SCSI adapter installed inside the computer.


SCSI interface is widely used in high-speed data transmission technology on minicomputers. The SCSI interface has the advantages of wide application range  ,   multitasking  ,   large bandwidth  ,   low CPU occupancy  ,   and hot plugging.


A host adapter and eight SCSI peripheral controllers can be connected to the SCSI bus  ,   and the peripherals can include disks  ,   tapes  ,   CD-ROMs  ,   rewritable CD-ROM drives  ,   printers  ,   scanners  ,   and communication devices.

SCSI is a multitasking interface with bus arbitration. Multiple peripherals attached to a SCSI bus can work simultaneously. Devices on SCSI occupy the bus equally.


The SCSI interface can transmit data synchronously or asynchronously  ,   the synchronous transmission rate can reach 10MB/s  ,   and the asynchronous transmission rate can reach 1.5MB/s.


There are two types of SCSI connectors: built-in and external.


The appearance of the built-in data cable is the same as that of the IDE data cable  ,   but the number of pins and specifications are slightly different. It is mainly used to connect the optical drive and the hard disk. The 40-pin IDE cable has 40 wires  ,   the 40-pin ATA66 has 80 wires  ,   and the SCSI built-in has 40 wires. 50 stitches  ,   68 stitches and 80 stitches.


As for the SCSI external data cable  ,   there are the following specifications  ,   and their densities are not the same  ,   don't make a mistake.



Low-Density  ,  50-pin  ,  Male External 

Low-Density  ,  50-pin  ,  Female External

High-Density  ,  50-pin  ,  Male External

High-Density  ,  50-pin  ,  Female External

Low-Density  ,  50-pin  ,  Male Internal


Low-Density  ,  50-pin  ,  Female Internal
High-Density  ,  68-pin  ,  Male External
High-Density  ,  68-pin  ,  Female External 

High-Density  ,  68-pin  ,  Male Internal


High-Density  ,  68-pin  ,  Female Internal
VHDCI  ,  68-pin  ,  Male External
VHDCI  ,  68-pin  ,  Female External  



MDR Cable 14 Pin to 26 Pin


MDR 50 Pin Cable Connector


SCSI cable VHDCI to HPDB50


VHDCI 68 Pin Cable MDR SCSI  


LFH160 to 50-Pin D-SUB Cable


Tel : 0086-0139-2949-7934

Skype : james198585 


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MDR 50 Pin Cable ConnectorMDR Cable 14 Pin to 26 PinSCSI cable VHDCI to HPDB50 VHDCI 68 Pin Cable MDR SCSI  LFH160 to 50-Pin D-SUB Cable

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