Re: USB-RS232 adapters vs. machines w/real consoles.

> I decided to investigate my various USB-RS232 adapters.

> I have three Prolific pl2303-based adapters, one Belkin/MCT-based
> adapter and several KeySpan USA-19HS adapters.  [...various
> issues...]

> Watching "/var/log/syslog" on the Linux Mint system, it may be that
> I'm fighting with its "ModemManager" and it's hijacking my attempts
> to transmit anything other than BREAK.

Based on what you've described, my front-runner theory is that all the
troubles in the partially-working cases are due to your
serial-interface program fighting with something else for access to the
device.  Does lsof show anything else with the relevant device open?

My experience with USB serial ports attached to penguins is, like
yours, limited, but my experience is that, once other things have been
made to go away and stop trying to talk to it, they Just Work: I just
start serialconsole -daemon and client serialconsole instances work
exactly the way they should.  (Hmm, I should create a linux branch in
the serialconsole repo....)

> Under NetBSD/amd64-7.0_STABLE, the Prolific-based devices were fully
> functional.  The Belkin/MCT-based device failed to function in the
> same manner as under Linux Mint.

That's a moderate indication it's sick, especially since

> I'm fairly certain the Belkin/MCT adapter worked fine on NetBSD in
> the past.

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