sv(4) — Dell System V Release 4 Issue 2.2



SV(4)                    (Dell UNIX 2.1.0, 16 July 91)                    SV(4)


NAME
      sv - Dell SmartVu device driver

DESCRIPTION
      The sv (SmartVu) device driver allows access to the 4 digit front panel
      alpha-numeric display available on some Dell hardware systems.  This is
      provided as an information output device to the user.  The SmartVu's
      primary purpose is to display information that cannot be, or is not
      designed to be, displayed via the system console.  Examples include
      diagnostic results and error codes.  The SmartVu device can be utilized
      by the user through the /dev/smartvu device interface.  This interface
      allows the user to write applications that output information to the
      SmartVu display.

      The default usage by the Dell UNIX operating system is to display the
      string "UNIX".  Application and/or system error usage may override this
      display.

Ioctl Calls
      The following ioctl call can be used to change the output characteristics
      of the SmartVu device.  There is currently only one supported ioctl
      command:

      SVDELAY

      This can be used to set a delay between each character being displayed.
      The delay can be set using a granularity of 100 millisecond units.  The
      argument structure for this command is defined in /usr/include/sys/sv.h.

FILES
      /dev/smartvu
      /usr/include/sys/sv.h
      /etc/conf/pack.d/sv/Driver.o
      /etc/conf/pack.d/sv/space.c

SEE ALSO
      intro(2), ioctl(2) in the Programmer's Reference Manual.

DIAGNOSTICS
      The /dev/smartvu interface should be treated as a normal character
      device.  This device can only display a subset of the standard ASCII
      character set, which includes printable characters only.  Valid
      characters are those with hexadecimal values between 0x20 and 0x7f
      (inclusive), with three exceptions:

      A Carriage Return (0x0D) will reset the current display position to the
      leftmost unit.
      A Linefeed (0x0A) will clear the entire display without changing the
      current display position.
      A Tab (0x09) will behave exactly the same as a Linefeed.




10/89                                                                    Page 1



SV(4)                    (Dell UNIX 2.1.0, 16 July 91)                    SV(4)


      All other characters will return error ENXIO.

      Attempts to set the delay value via the SV_DELAY ioctl to a value less
      than 0 or greater than SV_MAXDELAY ( defined in /usr/include/sys/sv.h
      will return EINVAL.

      Attempts to send output to the SmartVu when the hardware does not support
      the device will return ENXIO.

      The /dev/smartvu device is a single-threaded device, so only one
      application may have it open at a time.  Attempts to open it multiple
      times will return EBUSY.

WARNINGS
      The SmartVu is a WRITE ONLY device.  Attempting to read from /dev/smartvu
      will not be fruitful.  It is not possible to obtain the current contents
      of the SmartVu display in this manner.

      For Dell 486D/xx systems, SmartVU will operate properly only when the
      floppy drive(s) are enabled via the onboard (planar) floppy interface
      controller.  If a disk controller for an ESDI or SCSI interface is added,
      the disk drives should still be attached to the onboard controller, and
      the floppy interface on the add-on controller disabled.































Page 2                                                                    10/89

Museum

Related Articles