SCSI(HW)                 XENIX System V                  SCSI(HW)



     Name
          scsi - Small computer systems interface.

     Description
          SCSI provides a standard interface for peripherals such as
          hard disks, printers, tape drives and others. SCSI is run
          via a host adapter card that can support up to 7 devices.

          The minor device numbering scheme for SCSI devices (for
          example, a hard disk) is the same as the standard minor
          device number scheme for non-SCSI devices.

          Each SCSI device has its own major device number.

     Notes
                          ___________________________
                         |                          |
                         | This functionality is not|
                         | applicable to -286       |
                         | distributions.           |
                         |                          |
                         |__________________________|

          Currently, the only SCSI host adapter card supported is the
          Adaptec AHA-1540 controlling 1 or 2 hard disks and 1 tape
          drive.

     Unsupported Tape Devices
          Although some tape drives are not supported (example:  DAT
          and 8mm tape drives), the SCSI driver permits the connection
          of these devices.  In order to use these tape drives you
          must create the special device files manually.  Here is a
          description of additional tape device nodes:
          Name            Major Minor   See Note       Tape Type
          __________________________________________________________________
          /dev/rct0       34+TID        0              1, 5        QIC, 9TLD
          /dev/brct0      34+TID        4              1, 6        9TLD, HS
          /dev/nrct0      34+TID        8       2, 5   QIC, 9TLD
          /dev/bnrct0     34+TID        12             2, 6        9TLD, HS
          /dev/hirct0     34+TID        16             4, 1, 5     9THD
          /dev/hibrct0    34+TID        20             4, 1, 6     9THD
          /dev/hinrct0    34+TID        24             4, 2, 5     9THD
          /dev/hibnrct0   34+TID        28             4, 2, 6     9THD
          /dev/urct0      34+TID        32             3, 5        QIC, 9TLD
          /dev/burct0     34+TID        36             3, 6        9TLD, HS
          /dev/hiurct0    34+TID        48             4, 3, 5     9THD
          /dev/hiburct0   34+TID        52             4, 3, 6     9THD
          Tape Type:







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     SCSI(HW)                 XENIX System V                  SCSI(HW)



          9THD   Nine Track Hi-Density Tape (reel-to-reel)
          HS     Helical Scan Tape drive (WangDAT/Exabyte)
          9TLD   Nine Track Low-Density Tape (reel-to-reel)
          QIC    Quarter Inch Tape Cartridge
          NOTES:

                This device will do a tape rewind and unload at the
                end of the operation (at close).

                This device will not issue a rewind to the device, but
                an unload will be issued. On some tape drives an
                unload implies a rewind will be done (at close).

                This device will issue a rewind, but no unload will be
                done (at close).

                This is used to set the tape operation to high density
                for reel-to- reel tape drives (at close).

                This device uses a 512 byte block size. For typical
                quarter-inch tape drives.

                This device uses a 1024 byte block size. To be used
                for devices, that do not have a fixed block size, such
                as a helical scan tape, or reel-to-reel tape. Using
                this device on a quarter inch tape drive will not have
                any effect.

          You cannot run mkdev tape to add drives other than the QIC
          type because they are not supported.  The default devices
          are /dev/rct0 and /dev/nrct0. To create the other entries,
          you will need to do:

               mknod /dev/name c 34+TID major minor
               (Reg.).DE
               Where name is a name from the left column in the
               drive table.  TID is the target ID of the SCSI tape
               drive you are installing.

          For instance, to create the /dev/urct0 device, with
          the tape drive target ID set to 2, you would enter the following:

               mknod /dev/urct0 c 36 32


     See Also
          hd(HW), tape(HW)








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