Subject: Re: com rumblings...
To: Greg Troxel <>
From: Garrett D'Amore <>
List: tech-kern
Date: 06/15/2006 08:46:27
Greg Troxel wrote:
> Garrett D'Amore <> writes:
>> I'm more interested in this for console type activity.   I suspect
>> *most* people only use serial ports for console ports and slower
>> peripheral accesses (signature readers, cash drawers, command channel
>> for other ICs, etc.)
> I use serial ports for a 28.8 modem link, to talk to a Garmin GPS
> receiver, to talk to a TrueTime XL-DC GPS timing receiver, as well as
> console (as the terminal, and the console).   So I think you should
> consider that running modems at 115 kbps (on a 56k downlink) is pretty
> normal, and people tend to use older machines as gateways.  For me,
> older is currently a Thinkpad 600, which is a 233 MHz P5.

That's not that old; I suspect that will be fine.
> As for performance, I would like a 100 MHz P5 class machine to cope
> fine with a modem (and a sparc classic to deal with 9600 bps from the
> Truetime, but you're talking abotu com(4)).  I suspect that's not that
> too hard, and I don't have any objections to what you are proposing.
I strongly doubt whether any P5 class machine is going to notice the
change.  I'm more concerned if folks are running 386's or 486's at <
50MHz.  Those machines are also the ones likely to have broken serial
ports (FIFOless, or busted FIFOs), and most likely to be hurt.  We can
also talk about m68k class machines running at ~20MHz.

I believe and hope that even those class machines should be able to run
at 9600.  Certainly the sparc machines should be able to.  (I have
changed com for sparc as well, btw.)

Garrett D'Amore, Principal Software Engineer
Tadpole Computer / Computing Technologies Division,
General Dynamics C4 Systems
Phone: 951 325-2134  Fax: 951 325-2191