Adding modems

Guidelines for non-supported modems

When configuring non-supported modems:

You may need to disable or reduce the level of data compression and error correction when using a modem for UUCP. If throughput seems too low, or you have failed transfers, disable these features.
Disable XON/XOFF flow control when using the modem for UUCP. The stop character (XOFF or DC3) can occur in the UUCP protocol data stream, and cause the transfer to fail. XON/XOFF passthrough mode may be usable.
Use ``Setting hardware flow control'' with your modem.

If you want to enable XON/XOFF when using the modem for cu(C), you must define an alternative dialer to that used with UUCP. This can be done by modifying and renaming the Dialers file entry, or by modifying and renaming the dialer program, such that you have one dialer definition for UUCP and another for cu. See the sysfiles(F) manual page for instructions.

To install your modem for dial-in or dial-out:

Make sure the serial port you have chosen for your modem is recognized at bootup (check /usr/adm/messages or use hwconfig(C)) and, if the modem is internal, make sure that the COM port does not conflict with any other device.
Use the disable(C) command to disable the modem and non-modem control ports, for example:

disable tty1a
disable tty1A
If you are going to use the line for dial-out, ensure that the serial port is owned by uucp, for example:

chown uucp /dev/tty1A
chgrp uucp /dev/tty1A
If you intend to use the modem for dial-in, check the /etc/inittab file and confirm it has an entry for your port similar to this:
```
Se1A:2:off:/etc/getty -t60 tty1A m
```
/etc/inittab determines whether the port has a login prompt and defines the serial line characteristics. There should already be an entry for the line you are using; all you need to do is check the last field. This field is a number or letter (label) from the /etc/gettydefs file. See ``Serial port speeds, line-mode labels, and UART limitations'' in ``Configuring a serial port'' for a list of the more commonly used labels.
Do not alter any fields other than the gettydefs label. For example, if you want to connect to the modem at 19,200bps on the first standard serial port, the line should be similar to this:
```
Se1A:2:off:/etc/getty -t60 tty1A n
```
If you make any changes, use the following command to check the entries:

grep -i tty /etc/inittab
where tty is the serial port being used. This should generate only two lines: one for the modem control port (such as tty1A) and one for the non-modem control port (such as tty1a).
For more information on the /etc/inittab file and the various control codes, see the getty(M) and inittab(F) manual pages.
Duplicate any changes you make to /etc/inittab in the /etc/conf/init.d/sio file.
WARNING: Each time the kernel is relinked (when a driver is added or a tunable parameter is changed), /etc/inittab is reconstructed from the entries found in /etc/conf/init.d/sio.
Add the correct entries to the /usr/lib/uucp/Devices file. This file should have two entries for each serial port being used for a modem. One of the entries is used when you start a call using the modem (the Automatic Calling Unit (ACU) line), and the other line is used to connect directly with the modem to issue commands manually (the direct line). For an AT-compatible modem connected at 19,200bps on COM1, the entries in /usr/lib/uucp/Devices should be:
```
ACU  tty1A - 19200 /usr/lib/uucp/dialHA24 \T
Direct  tty1a - 19200 direct
```
The /usr/lib/uucp/dialHA24 entry is the dialer program for the modem. Two types of dialer programs are included to support a wide variety of modems; see -1 for more information.

Now follow the procedures in ``Configuring modems manually'', ``Configuring remote connections'', and ``Testing your modem connection'' to complete the installation of your modem.