HowTo: bidirectional serial ports under Amiga Unix

[Rich Skrenta]

	How to setup bidirectional serial ports under Amiga Unix SVR4

Disclaimer:
	You may need to do more or less than what I describe depending
	on what version of Amiga Unix you have.

First, check that you have the ttymon port monitor running.  Issue the command

	sacadm -l

You should see something like:

	PMTAG          PMTYPE         FLGS RCNT STATUS     COMMAND
	inetd          inetd          -    0    ENABLED    /usr/sbin/inetd
	ttymon         ttymon         -    0    ENABLED    /usr/lib/saf/ttymon

If you DON'T see the ttymon service listed, add it with the command

	sacadm -a -p ttymon -t ttymon -c /usr/lib/saf/ttymon -v 1

You only need to do this once.  The sacadm command will modify the file
/etc/saf/_sactab and alert the sac daemon that a new service has been added.

Now setup your ports.  1.1 system may already have some preconfigured port
monitors in place; I suggest removing them before adding your own.

Suppose we want to put a Telebit locked at 19200 baud on port #1 (couting
from zero) of the 7 port serial card (/dev/term/ql01).

First remove any port monitors that already exist on this port:

	pmadm -r -p ttymon -s ql01

Now add your own with the command:

	pmadm -a -p ttymon -s 1 -i root -fu -v`ttyadm -V` \
	-m "`ttyadm -d /dev/term/ql01 -bhr0 -t150 -l 19200M -s /usr/bin/login \
	-m ldterm -p \"ql01 login: \"`"

The pmamd commands to start port monitors are so long that I like to keep them
around in files, so I can just say "sh ql01", "sh ql05", etc. to start port
monitors.  I suggest saving the above pmadm command in a file and editing
the baud rate, device, etc. as needed.

See the pmadm and ttyadm man pages for a full description of the flags.

The important ones: '-t150' is a timeout in seconds.  '19200M' is the baud
rate cycling entry from /etc/ttydefs. '-bhr0' means "bidirectional, hangup,
r0 means wait for any one character before spitting out login:".  r1 would
wait for one CR before putting out the login:, r2 would wait for two CRs, etc.

pmadm will modifiy the file /etc/saf/ttymon/_pmtab.  

The complexity of the pmadm command may be daunting, but it's not much
trouble to maintain if you keep it in a file somewhere.  And it's neat
to only have one daemon managing all of your logins.

-- 
skrenta at amix.commodore.com