Re: UDB 166 serial port lossage

Hunter Andreas Ware (
Sun, 10 Nov 1996 19:22:14 -0500

System: redhat 4.0
linux 2.0.18
UDB 166
USR Sportster 33.6


com1 on UDB (I don't have a splitter) runs at a max of 38400. At 57600
and 115200 it gets into a really weird foodfight with the modem for every
keypress, seeming to echo the character eventually (but the modem doesn't
give result codes or anything). (This is all tested through minicom). I
have eliminated the 'extra signals confusing modem' possibility by running
it through a 9-pin serial cable with adapters on either end (it behaves
the same regardless).

Is this a known problem with the UDB? Have I done something stupid?
Should I just get a splitter and run it off of com2?

Also, with the modem on com1 the system doesn't like to boot properly (and
also the ARC loader and MILO like to chat with the modem, which is not my
favorite thing and may force me to put the modem on com2 regardless).
RedHat hangs going into runlevel 3. If I leave the modem turned off it
boots fine.

I have the _exact_ same problem, and can give a little further info.
This problem is not modem specific as it also holds when I try to make a
direct null-modem connection to a know good machine (Intel-Linux). At any
speed above 38400 the connection is Foobar'd. At 38.4k the udb has no
communication problems. This problem is new to RH4.0, I never had problems
at 115k with either modem or null modem slip connection with RH3.0.3.
Any ideas Erik?


               If the good lord had wanted man to stay on
        ._ O     the ground, he would have given us roots.
~~~\      //\.
    \    \>> |   Don't take life seriously, you'll never get out alive.
     \    \\
      \                 Hunter Ware -

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