Hardware manual

ZyXEL is a control program for ZyXEL U-1496 modems. It handles dialin, dialout, dial back
security, FAXing, and voice mailbox functions.
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SLIP and PPP software (if not in your Linux distribution) can be found at
ftp://metalab.unc.edu/pub/Linux/system/network/serial.
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14.2 kermit and zmodem
For use of kermit with modems see the Modem-HOWTO. One can run zmodem within the kermit program.
To do this (for ttyS3), add the following to your .kermrc file:
define rz !rz < /dev/ttyS3 > /dev/ttyS3
define sz !sz \%0 > /dev/ttyS3 < /dev/ttyS3
Be sure to put in the correct port your modem is on. Then, to use it, just type rz or sz <filename> at the
kermit prompt.
15. Serial Tips And Miscellany
15.1 Serial Modules
Often the serial driver is provided as a module(s) such as generic_serial.ko. Drivers for USB serial ports and
multiport cards are often provided as modules. Linux should automatically load any needed module, so in
most cases you have nothing to do.
But sometimes you need to configure Linux to load certain modules or gives parameters to the module or to
the kernel.
Such parameters may be supplied to certain modules on the command line for the kernel or in /etc/modules,
/etc/modules.conf or /etc/modprobe.conf. Since kernel 2.2 you don't edit the modprobe.conf file but use the
program update-modules to change it. The info that is used to update modules.conf is put in /etc/modutils/.
The Debian/GNU Linux has a file named /etc/modutils/setserial which runs the serial script in /etc/init.d/
every time the serial module is loaded or unloaded. When the serial module is unloaded this script will save
the state of the module in /var/run/setserial.conf. Then if the module loads again this saved state is restored.
When the serial module first loads at boot-time, there's nothing in /var/run/setserial.conf so the state is
obtained from /etc/serial.conf. So there are two files that save the state. Other distributions may do something
similar.
Serial modules are found in subdirectories of /lib/modules/.../kernel/drivers/. For multiport
cards, look in the serial subdirectory and/or char. For USB serial, look in the usb/serial
subdirectory. The module, parport_serial is for PCI cards that contain both serial and parallel ports.
As a last resort, one may modify the serial driver by editing the source code. Much of the serial driver is found
in the file serial.c. For info regarding writing of programs for the serial port see
Serial-Programming-HOWTO. It was revised in 1999 by Vern Hoxie but that revision is not at LDP.
Serial HOWTO
14.1 List of Software 56