Re: serial port real versus effective speeds

["James R. Van Zandt" <jrv vanzandt mv com>]

Rudy -

If your kernel was configured to support a serial console, you can
just add a kernel option like "console=ttyS1" to the lilo
configuration file or the loadlin command line.

If that doesn't work, you may need to reconfigure your kernel sources,
answering "yes" to the question "Support for console on serial port".
You also have to configure serial port support, of course (you can't
just load in a module).  Then, compile and install.

		   - Jim Van Zandt


>From: "A. R. Vener" <salt aero-vision com>
>Date: Mon, 26 Jun 2000 09:24:03 -0400 (EDT)
>
>Hi,
>
>I'm giving emacspeak a rest for now after many long
>and frustrating hours with it. For me the learning
>curve is not worth the loss of productiveity I'd have 
>to endure until I figure out all its idiosyncrasies.
>
>I've finally set up my Caldera system to use a serial
>port to connect to a DOS box running Telix and Vocal Eyes.
>
>After several false starts this process finally boiled down
>to the following step:
>
>Edit the /etc/inittab file and add this line after the
>existing getty lines:
>
>s7:2345:respawn:/sbin/getty /dev/cua0 default vt100
>
>s7 is just a unique tag name I picked basically out of the blue, I was going
>  to use s0 until I discovered another inittab line used it during startup.
>
>default - is the name of an entry in /etc/gettytab, this is where
>  the serial port parameters such as baud rate is set.
>vt100 - termcap entry
>
>
>
>This seems to work. For some reason I haven't yet figured out, the
>/dev/ttys0 device does not work, although all the documentation I've
>read said to use ttys0 for DOS com1 and ttys1 for DOS COM2. 
>Does anyone know why this is so?  I stumbled across the 
>/dev/cua0 device name when I was reading the setserial manual
>page.
>
>
>This brings me to another problem.  Although I can set the Linux
>port and Telix ports to the same speeds and everything works, there
>seems to be some sort of delay introduced which reduces the 
>effective transfer rate to under 9600 baud.  This happens regardless
>of the actual speed to which I set the serial ports. It is obvious that
>the ports are using the correct bit rates since  I only get the login prompts
>and a working connection if I match Telix and to the Linux serial port. But
>even at 38400 a screen refresh takes several seconds.  Has   Has  anyone 
>encountered this problem and fixed it?
>
>Also, is there a way to set up Linux so that it uses the serial port as 
>its console during boot?  I'd like to be able to trap the boot up messages.
>
>Thanks,
>
>Rudy