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/ SCSI School University

StarTech University offers computer enthusiasts and IT professionals a chance to learn more about new technologies and innovations in the IT world. Take some time to review the material, then pass the exam to earn your printable certificate for each course.

Course 2: SCSI School

Chapter 4: SCSI Signals

Types of SCSI Signals:

  • Single Ended (SE)
    Most SCSI devices use "normal" SE signaling, which limits the maximum length of a SCSI bus to 1.5m (4.9ft).This includes most 50-pin (Narrow) SCSI devices such as scanners and Zip drives.
  • High Voltage Differential (HVD) (also known as "Differential")
    A Differential SCSI system provides reliable signaling in high noise environments over a long bus length (up to 25m [82ft]). HVD hardware cannot be mixed with other SCSI signal types. A Differential bus requires Differential terminators.
  • Low Voltage Differential (LVD)
    A typical multimode LVD/SE SCSI system provides a moderately long bus length (up to 12m [39ft]) and downward compatibility with SE hardware. LVD-rated equipment is required for "Ultra" SCSI standards.


Next — Chapter 5: SCSI Types & Specifications