adp(7)                          (RM400 only)                         adp(7)

NAME
     adp - interface to the Adaptec ADP174x SCSI host adapter

SYNOPSIS
     /dev/ios0/sconxx

DESCRIPTION
     The EISA/IOS subsystem of the RM400 consists of up to four Adaptec
     ADP174x SCSI host adapters (ios0/sconxx) and SCSI device files [refer
     to sdisk(7) and stape(7)]. It is connected to the system via the EISA
     bus.

     ios0/sconxx provides access to the Adaptec ADP174x SCSI host adapter
     through the device files in the /dev/ios0 directory. The xx in the
     name of the SCSI host adapter stands for the logical number of the
     host adapter with an offset of 4. This is always specified as two
     decimal digits in the range 04 to 07.

MAJOR-MINOR DEVICE NUMBER
     The (32-bit) major-minor device number is defined as follows:

          000MMMMM MMMMMM00 00000000 000000yy

     M    The major device number.

     y    The logical number of the host adapter on the EISA bus.

IOS DESCRIPTION
     Up to 4 SCSI host adapters of the Adaptec AHA174x family can be
     installed on RM400 systems. A mixture of both host adapters with a
     single-ended interface (ADP1740A) and host adapters with a differen-
     tial interface (ADP1744) can be used here. Each Adaptec ADP174x SCSI
     host adapter supports a SCSI bus with up to seven SCSI devices.

IOS CONFIGURATION
     The Adaptec ADP174x SCSI host adapters are identified and initialized
     when the system is loaded.

     The SCSI-ID of the SCSI host adapter is fixed to 7.

     However, it is important that no device is connected to the SCSI bus
     with the same SCSI-ID as the bus.

     A unique logical device number is assigned to the individual host
     adapters when they are first recognized, which enables additional host
     adapters to be added without the device numbers of the devices already
     connected to the existing host adapters being changed.

     In general, the device file for the SCSI host adapter is not used. The
     character special device is provided instead as a debug entry point to
     allow manipulation of the host adapter.




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adp(7)                          (RM400 only)                         adp(7)

DIAGNOSTICS
     Messages are output in the following format for the Adaptec ADP174x
     SCSI host adapter:

          ios0/scon04: nextlpb != getlpb

     where:

     ios0/scon04:  The Adaptec ADP174x SCSI host adapter where the error
                   occurred. In this case, the error occurred on the host
                   adapter at the EISA bus with logical number 0.

FILES
     /dev/iosb/sconxx

SEE ALSO
     devname(7), sdisk(7), stape(7).





































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