hada(7)                          DG/UX 5.4.2                         hada(7)


NAME
       hada - link an AViiON bus to a High Availability Disk Array subsystem

SYNOPSIS
       hada ([def]) or
       hada @devicecode(adapaddr)

DESCRIPTION
       The hada adapter allows an AViiON server to access a High
       Availability Disk Array (H.A.D.A.) system. The adapter links a host's
       VME bus to group of Small Computer System Interface (SCSI) buses.

       There are two device specification formats, shown above.  The first
       format accepts default values. The second format specifies all
       values:

        def         is a hexadecimal number (range 0-3), selecting a default
                    device code and VME address for the adapter. Null equals
                    0.

        devicecode is the hexadecimal device code of the adapter preceded
                    by the @ character.

        adapaddr   is the adapter's hexidecimal VME address.

       Four short-hand defaults are provided.  They are: hada(0), hada(1),
       hada(2), and hada(3), which  correspond to the device code/base
       address pairs: 70/FFFF1000, 71/FFFF1400, 72/FFFF1800, 73/FFFF1C00.

       This adapter supports two basic device types: disk-array units, and
       general-purpose SCSI units.  Each disk-array unit may be composed of
       a disk array (three or more disks), a disk mirror (two disks), or a
       single disk.  They are accessible only through the disk array device
       driver, da(7), and must be associated with a particular controller
       using the gridman(1M) utility before they may be used.  Refer to
       da(7), and gridman(1M) for more detail.

       An additional SCSI bus is used for general-purpose SCSI devices.
       This bus supports a maximum of six SCSI devices, whose SCSI IDs range
       from zero to five, inclusive.  Devices on this bus may be accessed
       using the DG/UX SCSI adapter interface described in Writing a
       Standard Device Driver for the DG/UX System.  No special preparation
       with gridman(1M) is required before devices on this bus may be used.
       They are permanently associated with unit numbers zero through five.

SEE ALSO
       sd(7), st(7), da(7), gridman(1M).










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