C H A P T E R  7

Setting Terminal Options with the sitty Utility

This chapter describes how to set the terminal options using the sitty utility, including;

Using the sitty Utility

The utility program sitty sets and displays the terminal options for the
SunSAI/P adapter software.

The sitty command must be run each time the machine is booted if non-default settings are required for certain ports. Usually, the best way to do this is by adding sitty commands to your system initialization file. (You can put them in a text file in the /etc/rc2.d directory, and give the file a name such as /etc/rc2.d/S99saip or /etc/rc2.d/S99sittystuff; refer to the Solaris System Administration Guide for details.) Alternatively, you can include the sitty command sequence in your .login or .profile files. Your system administrator can help you edit these files. The full pathname for the command is /opt/SUNWconn/bin/sitty.

The format is:

sitty [-a] [option(s)] [< ttyname]

With no options, sitty displays all SunSAI/P special driver settings, modem signals, and all standard parameters for the TTY device referenced by standard input.

Setting the sitty Command Options

Command options are provided to change flow control settings, force modem control lines, and display all TTY settings (see TABLE 7-1). Any unrecognized options are passed to stty(1) for interpretation.


TABLE 7-1 sitty Options




Displays all unique SunSAI/P option settings, as well as all of the standard TTY settings reported by stty -a.


Sets and displays options for the given TTY device, instead of standard input. ttyname is the full pathname
(e.g. /dev/term/a000) of the device.

The following options specify transient actions to be performed immediately.


Sends a 250 MS break signal out on the TTY line.


Immediately flushes (discards) TTY input and output.


Flushes TTY input only.


Flushes TTY output only.

The following options are "sticky", which means that the effects continue until the system is rebooted or until the options are changed.


Alters the baud rate tables, so that the following baud rate changes take place: 50=56700, 75=76800, 110=115200 , 200=230000, 300=76800, 600=115200, 1200=230000, and 1800=28800.


For example, 50 baud becomes 57,600 baud, 75 baud becomes 76,800 baud, and so on.


Disables [re-enables] carrier sense, so the TTY may be opened and used even when carrier is not present.


Switches the function of the DSR and the DCD inputs on the modular connector, so that DCD is available when using an 8-pin RJ-11 connector instead of the 10-pin RJ-45 connector.

edelay n

Sets the number (n) of milliseconds of delay between the time the first character arrives after a period of no characters and notification of its arrival to the host. This delay is also referred to as the wakeup rate between the host adapter software (FEPOS) and the host device driver. This has the advantage of reducing host overhead by allowing the host to process larger blocks of incoming data.


Larger edelay values result in more characters being sent in a given time period. This will reduce host processor overhead and increase overall system throughput. Smaller edelay values result in fewer characters being sent in a given time period. This will increase character response time and increase host processor overhead.


The default value for edelay is 100. This is a good value for normal TTY activity such as typing. For some applications like uucp, decreasing the edelay value may increase character throughput, but will result in increased system overhead. For applications receiving continuous input at high speeds, increasing edelay will result in lowering host overhead and increasing overall system throughput. A value of 250 is reasonable.

The following options specify actions which are not "sticky", meaning that the changes are reset when the device is closed, and that the device will use the default values the next time it is opened.


Stops output exactly as if an xoff character was received.


Restarts stopped output exactly as if an xon character was received.


Activates flow control to stop input.


Releases flow control to resume stopped input.


Raises [drops] the DTR modem control line, unless DTR hardware flow control is selected.


Raises [drops] the RTS modem control line, unless RTS hardware flow control is selected.


Enables [disables] RTS hardware input flow control, so RTS drops to pause remote transmission.


Enables [disables] CTS hardware output flow control, so local transmission pauses when CTS drops.


Enables [disables] DSR hardware output flow control, so local transmission pauses when DSR drops.


Enables[disables] DCD hardware output flow control, so local transmission pauses when DCD drops.


Enables [disables] DTR hardware input flow control, so DTR drops to pause remote transmission.

For more information, refer to the sitty(1), stty(1), ioctl(2), termio(7i), and terminfo(4) man pages.