sasy(7)              INTERACTIVE UNIX System              sasy(7)



          NAME
               sasy - SunRiver asynchronous serial port

          DESCRIPTION
               The sasy driver supports both serial ports on the SunRiver
               Cygna 386 Station.  If a station is not connected, an
               attempt to open its serial ports will fail.  The ports can
               be programmed for speed (50-19200 baud), character length,
               and parity.  Output speed is always the same as input speed.
               The ports behave as described in termio(7).

               The asynchronous port is a character-at-a-time device for
               both input and output.  This characteristic both limits the
               bandwidth which can be achieved over a line, and increases
               the interrupt loading on the central processor.  In particu-
               lar, file transfer programs such as uucp(1) may not function
               well at speeds over 9600 baud.

               If the port was opened with the modem control bit present in
               the minor device number (see below), modem control will be
               enabled.  If enabled, the driver will wait in open until
               Data Carrier Detect is present.  Once opened, if Data Car-
               rier Detect drops, the driver will return errors on any sub-
               sequent reads or writes of the asynchronous port by the
               user.  If the port was opened as a controlling teletype,
               signal SIGHUP will be generated to the process which did the
               open.

               The baud rates of the serial adapter programmable baud-rate
               generator do not correspond exactly with system baud rates.
               In particular, setting B0 will cause a disconnect, setting
               EXTA will set 19200 baud, and setting EXTB will set 38400
               baud.  It is not possible to directly set 2000, 3600, or
               7200 baud.

             Minor Device Numbers
               The asynchronous port is a character device.  The low-order
               4 bits (bits 0-3) of the minor device number correspond to
               the station at which the port is located.  Bit 4 enables
               modem control on the port.  Thus, minor device 0 corresponds
               to the system board serial port with no modem control, while
               minor device 16 corresponds to the same port with modem con-
               trol enabled.

          FILES
               /dev/ser*

          SEE ALSO
               asy(7), slp(7), termio(7).
               signal(2) in the INTERACTIVE SDS Guide and Programmer's
               Reference Manual.

          ADDED VALUE


          Rev. 1.2                                                   Page 1

          sasy(7)              INTERACTIVE UNIX System              sasy(7)



               This entry, supplied by INTERACTIVE Systems Corporation, is
               an extension of UNIX System V.





















































          Rev. 1.2                                                   Page 2