Baslinux mailing list

[David Moberg <davidjmoberg AT gmail.com>]

I have an LTmodem, which is a software modem. It's essentially
a sound card that is connected to a phone line. Unlike a real
modem, which has code in firmware to translate modem
commands into dial tones, a software modem requires you to
use a chipset-specific driver. The driver does what the firmware
code would do on a real modem.

These modems are very common. They come in both ISA and
PCI versions, and the ISA versions will apparently work on a
486 (search for 486+ltmodem).

You can search online for the FCC-ID that is on your modem
and see if it is an LTmodem. Or try a diagnostic program like
lspci (in pciutils package) or isapnptools to identify your
modem.

It is possible to use the LTmodem on BL3.32, with a 2.2.16
kernel. First you need to download two files: ppp2214.o and
linux568.zip.

http://walbran.org/sean/linux/stodolsk/ppp2214.o
http://linmodems.org/linux568.zip

Use the web archive machine (archive.org) if these links are
dead by the time you read this.

The md5sums are:

7c43bf94ae6cd91ab13c2bbb435fe43b ppp2214.o
48d34107e1d4e146d950435245aa5276 linux568.zip

The BL3.32 (2.2.16) PPP driver has a small bug in it, which
shows up in unusual situations like this one. Before you do
anything else, fix it by removing and replacing
/lib/modules/2.2.16/misc/ppp.o with ppp2214.o (rename
ppp2214.o to ppp.o). This will make sure that the old ppp.o
does not get accidently inserted. If it does get inserted,
Linux will panic when you try to connect.

Now you can install the ltmodem driver itself. unzip
linux568.zip into a temporary directory and copy
ltmodem.o to a more convenient location. I suggest
/lib/modules/2.2.16/misc/ltmodem.o. You may delete
the temporary directory, as the scripts provided with
linux568 are not very useful on BL3 (they are
designed for a multi-user system).

mknod /dev/ttyS14 c 62 78

You can set up a symlink: /dev/modem -> ttyS14
if you want. After you insmod ltmodem, you are
ready to connect. Just use the /dev/ttyS14 or
modem port with microcom, eznet, or whatever
you are using.

You can probably use a similar method in BL2,
because it has the same kernel. There are just a
couple of roadblocks: first, in BL2 you need to use
the -f option with insmod, and secondly, you need
to get a copy of unzip, becuase BL2 does not
come with one. On BL2 or BL3 (after a multi-user
upgrade) the ltinst script should work.

This will not work with BL3.4 or BL1 (different kernels).

In testing, the LTmodem with this driver appears to
work with at least v.90 speeds.

David