Hardware manual

this you likely will have to reconfigure minicom and then exit it and restart it. Instead of all this bother, it may
be simpler to just reboot the PC or via using a virtual terminal kill the process using "top" (or "ps" to get the
process number and then "kill" to kill that process.
The obsolete redirection method (which still works in later versions) is to type ``stty ... < /dev/ttyS2''. If the
new method using -F works but the obsolete one hangs, it implies that the port is hung due to a modem
control line not being asserted. Thus the obsolete redirection method might still useful for troubleshooting.
11.5 What is isapnp ?
isapnp is a program to configure Plug-and-Play (PnP) devices on the ISA bus including internal modems. It
comes in a package called "isapnptools" and includes another program, "pnpdump" which finds all your ISA
PnP devices and shows you options for configuring them in a format which may be added to the PnP
configuration file: /etc/isapnp.conf. The isapnp command may be put into a startup file so that it runs each
time you start the computer and thus will configure ISA PnP devices. It is able to do this even if your BIOS
doesn't support PnP. See Plug-and-Play-HOWTO.
11.6 Connecting two PCs together via serial ports
This is where you run a serial cable (crossover type = null-modem type) between the serial ports of two PCs.
Then how do you use this line? One way is for one PC to run login on the serial line and for the other PC to
run say minicom or picocom to emulate a terminal. See Text-Terminal-HOWTO. There is no network
protocol used in this case and no error detection.
The other method is to run a network protocol on the line. For example, to use PPP in combination with
TCP/IP see Serial Laplink HOWTO. Although this HOWTO doesn't mention the old program "slattach"
(serial line attach) it can put the serial line into a networking mode using the protocol you select. Protocols for
slattach include PPP or SLIP (an older protocol widely used prior to PPP).
The Debian package, net-tools, contains slattach. SLIP is provided as a kernel module or can be built into the
kernel (2.2, 2.4, or 2.6).
11.7 Connect the serial port to a fast network: ser2net
ser2net is a Linux program which will connect a network to the serial port. For example, someone connects to
your PC via an ethernet port or fast modem using say telnet. Then (without ser2net) they could remotely login
to your PC and then run programs on your PC that utilize a serial port on the PC. However, it might be better
if they didn't need to login and use your software, but instead could immediately connect to the serial port.
ser2net running on your PC can make this happen.
It could be like a bridge between the ethernet cable and the serial cable. The ethernet cable would have
TCP/IP protocol on it but the serial port would just have the raw data taken out of the TCP/IP packets.
Optionally, you could use TCP/IP packets on the serial line too. Since an ethernet port has high bandwidth, it
could communicate with several serial ports at the same time and also have data flowing elsewhere as well.
To set up ser2net, you must specify which network ports (on the ethernet) will connect to which serial ports.
Then when network packets arrive at your PC over ethernet which are addressed to a network port you've tied
to a serial port, the data in those packets flows to the serial port. And conversely. Of course the network
doesn't have to be ethernet. It could be a cable modem or DSL line, etc.
Serial HOWTO
Obsolete redirection method 51