Re:Using both serial ports at the same time, Summary please ...

Nicholas J. Leon (nicholas@binary9.net)
Tue, 14 Oct 1997 16:00:52 -0400


At 12:16 PM 10/12/97 -0700, Mr. James W. Laferriere Network Engineer wrote:
>
> Hello Nicholas, Please be kind & post a summary ? Tia, JimL

Ok, it was pretty straight forward:

The problem
-----------
I could only open and use 1 serial port of my 2 built in ones at the same
time. They were set for the normal IRQ' and ports for COM1 & COM2.

If I had one open (say a PPP connection) and attempted to use the other
(say, as a serial terminal [agetty ttyS1 9600]), both would SLOW DOWN to
amazing levels (like 10 characters per minute).

As soon as I closed either port, the other would come back up with no
problems and no errors.

All the time, the kernel never reported any problems. I did not test this
under any other OS than Linux as I don't have any other installed on that box.

I tried in my AMI bios to move the serial ports to various other settings
(ie, COM1-COM4) to no effect.

The solution
-------------
I put in an internal modem into my 'puter, set it as COM3 and dialed out to
my PPP account.

I then attempted to use on of the two inboard ports. No problems!! If I
tried using all three, the two built-in ones would exhibit the same problem
as before, but the third would happily buzz along.

The Results
------------
My mobo's serial ports are fried :( I traded my external 36.6 modem for an
internal variety and everything works as expected.

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simple is elegant nicholas@binary9.net
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