[nos-bbs] Re: Ubuntu 7.10 issues...

[Andy Nemec]

Hi, Folks.

Regarding Chris' problems:

 > >
 > >  > This isn't NOS specific, but I think the discussions have been on this
 > >  > list about this.
 > >  >
 > >  > The issue is basically that the packet data seems to shift around as
 > >  > far as TX Delay and TX Tail.  It isn't consistent in the 'window' so
 > >  > to speak.

--------------------Snip----------------------

 > >  > I have a TNC I run in KISS mode and two different soundcard
 > >  > interfaces, one traditional with a serial interface for keying and one
 > >  > (Tigertronics) that does its own keying.  The two soundcard interfaces
 > >  > behave themselves perfectly running psk and other HF digi modes in
 > >  > both linux and Windows.  In Windows all of them behave properly with
 > >  > 'normal' recommended settings.

This might sound dumb, but have you checked your setup for IRQs? I am 
wondering if you might not have some sort of conflict or precedence 
problem.

I once had an interesting problem with an older sound card. It worked 
perfectly as long as there were no writes to the disk. I would get a quick 
drop-out in sound when there was a write to the disk. This was on a 
Slackware linux box, (which really doesn't matter).

The problem had to do with IRQ precedence. As it was an older ISA card, it 
was using a lower-numbered IRQ. The disk IRQ is higher numbered and due to 
the way that a PC handles interrupts, it gets precedence. I installed a PCI 
sound card (which uses a higher-numbered IRQ) and the problem went away.

I am wondering if you may have a similar problem. Note that conventional 
serial ports use lower-numbered IRQs. I don't know all of the details of 
the system you are using with regard to hardware, so perhaps there is 
something unusual that keeps your serial port and sound card from operating 
correctly. Is there a possibility that you are using an older sound card 
that is conflicing with the comm port IRQ?

This might just be a dumb idea on my part, but perhaps it's worth checking 
out. Most of us don't worry about IRQs anymore, so it's easy to forget.

Good luck.


Andy Nemec
Internet E-Mail: kb9aln at tds.net
amprnet - kb9aln at kb9aln-5.ampr.org