1.3.3.5 SCSI Drives

  • SCSI vs ATA

    1. ATA has either 40 or 44 pin connectors. SCSI has many types and shapes.
    2. ATA accommodates up to 2 devices, SCSI can accommodate more than 2.
    3. DEvices on SCSI cable needs unique numerical identifier , which can be done by either jumper or software.
    4. Few SCSI devices have Read-Only mode.
    5. SCSI has no controller. It is designed as a bus, where different devices can communicate with each other.    

  • Types of SCSI

    1. SCSI normal transfers 8 bit at a time , wide transfers 16 bits at a time.
    2. Single Ended method (SE),  high voltage represents 1 and no voltage represents 0.
    3. Differential voltage method requires 2 wires for each bit. In case of 0 there is no difference, For 1 , one wire is set for +ve and another wire is set for opposite.

  • Connector Types

    1. Single Connector Attachment. has power and data wires together.

  • Size Barriers
    1. SCSI has no size barrier like ATA.
    2. if BIOS has some limitation , it may put some restrictions on storage capacity.
at

2.3.2 Essential & Non-essential data

  • 1.1.3.3 Types of Sector Addresses
    Physical address is address of the sector with respect to start of physical media. One way of addressing was to mentioning plate number , tr...
  • 1.1.2.1 CPU & Machine Codes
    CPU Central processing unit or processor. Can process assigned job. but cant create job for itself. OS assigns job to CPU. CPU picks up inst...
  • 1.1.1.3 Strings and Encoding
    How computer stores sentence ? Computer does not know characters and symbols. Computer has a unique numerical value for a symbol. Computer k...