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modem troubles, linux, redhat, x-windows

vedel asked
Medium Priority
Last Modified: 2013-12-15
Hello. I'm having a weird problem, hope somebody can help me.
I'm upgrading my linux system from an older slackware installation to
a new redhat one. Everything is fine except for one major obstackle -

 I cannot get in contact with my modem while in X-windows.
 If I dont go into x-windows minicom works correctly.

If, while in X-windows,
I try to use eg minicom or seyon they popup correctly and dont
report any errors, but they have no active contact with the modem,
like the initialization string didn't do its job properly.  As a result
the two programs doesn't accept keystrokes in the modem window, that is:
the cursor doesn't react if I try to type eg. atdtxxxxxxx, whereas all
other aspects of those programs works ok, like changing port setup etc.

 Both minicom and seyon works without any problems in my slackware
installation, and the setup of the modem port etc in the new redhat
installation is exactly  the same as in the old slackware installation.

What can going into X-windows possibly do which could prevent my
contact with the modem???

Let me list two other, but less irritating, weird things, which maybe
can help people with insight to diagnoze my problem:

a) When I leave x-windows in the redhat installation the console screen
gets filled with ugly signs (lines, clumps, masterspaces etc) not the
normal characters (plus some extra from the xinit session) which where
there before I entered x-windows. Similar any new keystroke produces a
weird sign, not at all a normal character.

b) in X-windows the keyboard setups are not exactly similar ( ie. xmodmap
-pke produces different results in the old slackware and the new redhat
installation), however, if running the redhat installation I try to do
xmodmap slackware.map (where slackware map is a dump of the total xmodmap
view of the slackware keyboard settings) I cannot do that, as xmodmap
finds it cannot create all the settings.

Thanks in advance for any help. Henrik Vedel, Copenhagen, Denmark.
Watch Question

check if terminfo is installed to fix your console problems.
use kppp from KDE to connect under X. It is great and the KDE-Help is good to understand whats happening.
KDE : www.kde.org or ftp.kde.org.
Check for mirrors, they are faster.


To avoid misunderstandings due to my crappy english let me
rewrite the question slightly:

1) My main problem is: I cannot get my modem to work correctly
(initialize) from within x-windows of my new redhat 4.2 linux

2) However, BEFORE entering x-windows the modemsoftware do work correctly in the redhat 4.2 linux installation.

3) On the same pc I have an older slackware linux installation. Using that I have no problems at all using my modem, neither
inside nor outside X-windows. (While the installation is somewhat
old the kernel is of the newer modular 2.0.something type.)

In other words. I have no problems setting up the modem
communication software, the ports, the hardwaresettings etc,
as its all been done previously and proven to function in
my slackware installation as well as in my redhat 4.2 installation. It just CEASES to function when I enter
x-windows in the redhat 4.2 installation.  

What happens is that a program like e.g. minicom, which normally
open for me with the three lines:
 "Press CTRL-A Z for help on special keys"
 "AT S7=45 S0=0 L1 V1 X4 &c1 E1 Q0"

instead stops after printing the first line:
 "Press CTRL-A X for help on special keys"
and remains inactive.

I presume it means it cannot initialize the modem.

What the heck is going on ???

Somehow x-windows must be chainging the bootup settings of
something - but I haven't got a clue about which settings
it is changing in an harmful way.   The XF86Config files
used on the slackware and the redhat installations are identical.

I can add one further peculiarity which might help the true
expert: Before entering x-windows on the redhat 4.2 installation
the console works fine. When returning all characters are turned
into weird symbol, bearing no resemblance to any human set
of characters (exept maybe hiroglyphs). The keyboard still
function correctly, I can for example do "startx" and get
back to x-windows, which works ok, but what's written on the
console is garbage.  I'm not concerned with this problem in
itself, just thought it might point somebody with insight towards
my real problem: the missing initialisation of my modem (or
contact to) while in X-windows on a redhat 4.2 installation of

Once again, many many thanks in advance for any help.
Henrik, Copenhagen, Denmark.
The garbled console is no big deal - thats simply a problem
with certain video cards (seen it on a Trident TGUI9440, and
also on a Trident 9680) - just type "setfont" when you get
back to the console and it will return it to normal.

Sounds to me like when you start X, something is pointing to
your modem device.   Does it say /dev/mouse in your XF86Config?
If so, make sure this symlink does not point to the serial
port that your mouse is on.  If you had a PS/2 mouse, and a
bad symlink in /dev (or simply a direct pointer in XF86Config
to your modems serial device) then it would exhibit the exact
symptoms you are describing.  If you have a PS/2 mouse, make
sure /dev/mouse is linked to /dev/psaux _not_ /dev/cua? (or

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Thanks for your sugestions.  

The console thing might work,  I'll try it out.  

However, I dont see how anyting in
the XF86Config file can point at wrong devices when the
very same XF86Config file works ok in my old slackware
installation. Then it could be symlinks, but the only one
I made, on top of what the redhat installation script
produces, was to create a dev/modem pointing towards
my modem port /dev/cua3, and as you'll see below I got it
to work without changing neither XF86Config nor symlinks.

In the meantime I did find a "solution" to my x-windows+modem
problems myself.  First I found out that if I use the
old slackware XF86_SVGA server-program from the slackware
installation in the new redhat installation
the problems disappear. Ie I could still get
into X-windows and the modem now works correctly. But a
second problem arose - on the redhat installation I was
only allow to run the old slackware XF86_SVGA as root, whatever
I tryed changing I couldt get around that.  Finally I
installed an old redhat version of XF86_SVGA (infomagic
6 cd set from 1996) on the new redhat installation and
now it works beautifully.  

The conclusion must be that either there is a bug in the
new versions of the XF86_SVGA servers which affect certain
machines like mine, or they need a
different version of the XF86Config file than do older

I have the problem that the autosetup XF86Config
tools doesn't allow me to get the resolution 1024*768  
I prefer to run X-windows in, wherefore I have had to trim and
taylor a "personal" XF86Config file, which I copied directly
to the new redhat installation. So if the new XF86_SVGA
servers need a slightly different setup file than the old
ones that could be
the reason for my problems.

However, the bastard didn't
report any errors. And with the old XF86_SVGA program
both the modem problem and the console problem went away!

Whatever the reason - now I'm a happy man running redhat
4.2 linux

Well thats not what I expected, but I'm glad everything
is working :)
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