NAME
        SetParams -- change parameters for the parallel device

   FUNCTION
        This command allows the caller to change the EOFMODE parameter for
        the parallel port device. It will disallow changes if any reads or
        writes are active or queued.

        The PARB_EOFMODE bit of io_ParFlags controlls whether the
        io_PTermArray is to be used as an additional termination criteria
        for reads and writes.  It may be set directly without a call to
        SetParams, setting it here performs the additional service of
        copying the PTermArray into the device default array which is used
        as the initial array for subsequent device opens. The Shared bit
        can be changed here, and overrides the current device access mode
        set at opendevice time.

   IO REQUEST
        io_Message      mn_ReplyPort initialized
        io_Device       preset by opendevice
        io_Unit         preset by opendevice
        io_Command      PDCMD_SETPARAMS (0A)
                        NOTE that the following fields of your iorequest
                        are filled by open to reflect the parallel device's
                        current configuration.
        io_PExtFlags    must be set to zero, unless used
        io_ParFlags     see definition in parallel.i or parallel.h
                        NOTE that x00 yields exclusive access, PTermArray
                        inactive.
        io_PTermArray   ASCII descending-ordered 8-byte array of
                        termination characters. If less than 8 chars
                        used, fill out array w/lowest valid value.
                        Terminators are used only if EOFMODE bit of
                        io_Parflags is set. (e.g. x512F040303030303 )
                        This field is filled on opendevice only if the
                        EOFMODE bit is set.

   RESULTS
        io_Error -- if the SetParams succeded, then io_Error will be null.
                    if the SetParams failed, then io_Error will be non-zero.