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atapi_ide(7)


NAME

  atapi_ide - Interface for ATAPI or IDE (PC) devices


SYNOPSIS

  PCI bus CMD/Acer ATAPI/IDE adapter:

     bus pci0 at *
      bus ata0 at *
      controller scsi0 at ata0 slot 0
      controller scsi1 at ata0 slot 1

  PCI bus Cypress ATAPI/IDE adapter:

     bus pci0 at *
      bus ata0 at *
      bus ata1 at *
      controller scsi0 at ata0 slot 0
      controller scsi1 at ata1 slot 0

  PCMCIA bus ATA/IDE disk card:

     bus pcmcia0 at *
      bus ata0 at pcmcia?
      controller scsi0 at ata0


DESCRIPTION

  Devices commonly known for their use on PC devices as ATA or IDE devices
  are supported using the SCSI CAM device driver.  The ATA standard has also
  been expanded to include what are known as ATAPI devices.  The SCSI CAM
  device driver is also used for those disks and CD-ROM devices. These
  devices may also be known under the names EIDE, ATA-2, Fast-ATA, or Ultra-
  ATA.

  Beacuse the ATA/IDE standard was not developed until after many of the
  devices that used this standard were produced, there are many devices which
  do not strictly comply with the standard.  While it is possible some
  industry standard devices may appear to work, it is also possible they will
  cause hang or data corruption cases when used under more stressful
  situations.  For this reason, it is recommended that only the supported
  devices be used.  These devices have been tested and are certified for
  correct operation.

  ATAPI/IDE controllers allow the connection of two devices.  These two
  devices are known as the master device and the slave device.	If only one
  device is connected, that device must be the master (slave-only
  configurations are not supported).  When used by the SCSI CAM device
  driver, the IDE master device is assigned SCSI id 0 for that controller.
  The slave device is assigned SCSI id 1 for that controller.  No other SCSI
  ids are assigned on that controller.	Most ATAPI/IDE adapters contain two
  channels (known as the primary and secondary).  Each of these channels may
  contain their own master and slave devices.  Therefore, a dual channel
  ATAPI/IDE controller may contain up to 4 devices (a master and slave pair
  on each channel).  These 4 devices are then accessed as SCSI id 0 and 1 on
  each channel.

  Many SCSI operations translate perfectly for use on IDE.  For example, read
  and write operations are the same.  However, many SCSI disk mode pages are
  emulated by the IDE device driver.  For example, you can display the SCSI
  inquiry mode pages using the following command:

       % scu show inq pages

  pages are created by the device driver to contain the long (full IDE) form
  of the device name, serial number, revision, and the operational modes of
  the device.  Only a shortened version of this information is available with
  the standard SCSI inquiry command.  Note also that the following command:

       % scu show pages

  Shows that the SCSI mode pages contain only partial information.  Only that
  information (such as geometry) that the drive reports to the system is able
  to be reformatted into these emulated SCSI mode pages.  Much of the
  information (such as RPM) is simply not available from the drive, and
  therefore not accurately reported.

  ATAPI devices are much more closely related to SCSI devices, and as such
  contain their own mode pages.	 Therefore, for these devices, the mode page
  values reported are those from the device, and no emulation is involved.

  ATAPI tape devices are not supported at this time.


FILES

  /dev/disk/dsk???

  /dev/disk/dsk???


SEE ALSO

  SCSI(7), rz(7), and disklabel(8)

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