How do I boot 6.0-BETA2 iso with rs232 console?

[Dieter]

AMD64 machine, booting
-r--r--r--  1 root  wheel  50087936 Aug 22 17:57 6.0-BETA2-amd64-bootonly.iso
from a dvd.

Console is rs-232, 19200 baud.

I get:


Enterfrom CD : Boot from CD :
CD Loader 1.2

Building the boot loader arguments
Looking up /BOOT/LOADER... Found
Relocating the loader and the BTX
Starting the BTX loader

BTX loader 1.00  BTX version is 1.01
Consoles: internal video/keyboard
BIOS CD is cd0
BIOS drive A: is disk0
BIOS drive C: is disk1
BIOS drive D: is disk2
BIOS 608kB/2096064kB available memory

FreeBSD/i386 bootstrap loader, Revision 1.1
(root at portnoy.cse.buffalo.edu, Tue Aug  2 19:52:27 UTC 2005)
Loading /boot/defaults/loader.conf
/boot/kernel/kernel text=0x54ea08 data=0xaca68+0xdd308 syms=[0x8+0x8de58+0x8+0x7
5b4a]
\
Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [/boot/kernel/kernel]...
\



And then nothing.  I suspect it has switched the output from rs232 to video.

I can type a key and get the "OK" command prompt as promised.
Typing "?" or "help" prints stuff out using only the bottom line
of the screen, unreadable.

I tried typing "-h" <return> as suggested on
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/serialconsole-setup.html

and get "not found" (and maybe something else, the cursor jumps around,
resulting in scrambled output)

"-h" results in:

[...]
Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [/boot/kernel/kernel] in 8 seconds...
OK not found a list of commands, 'help' for more detailed help.

"?" results in:

[...]
Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [/boot/kernel/kernel] in 8 seconds...
OK how-module      show module load dataoduleeen autoboot help.

"help" results in:

[...]
Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [/boot/kernel/kernel] in 8 seconds...
OK      most available commands. available.  Use the '?' command to list


Question:

	Is there some magic string I can type at the OK prompt to set the
console to rs-232, 19200 baud, and then boot the kernel?


Suggestion:

	For maximum portability, do not assume that you know the terminal
is some specific type (ansi, sun, tek4107, vt100, wyse, xterm, whatever).
Don't use those fancy cursor movement thingy-bobbers.  Just assume you
are talking to an old teletype with a big roll of yellow paper.  I don't
think the boot blocks have room for a 500KB termcap file.  Besides,
some of us don't know what type of terminal our terminal emulator is
emulating.


thanks