HELP: soundmodem & keying rig

[Bob Billson <reb@bhive.dhs.org>]

Hi all...

I have a problem getting the soundmodem driver working with my Potato box.
I am running the 2.4.5 kernel on a really bare 486/66 machine.  It has a
base Potato install on a 100 MB hard disk, ax25utils Debian package, network
card, SoundBlaster 16, serial/parallel ports and that's it.  (The machine will
be used for remote weather data collection experiment, so it doesn't need a \
lot of extras.)

The problem is keying the rig (Radio Shack HTX-202 HT).  I built the 
soundmodem driver and it seems to work.  I can set up a device sm0 and create
a route to it.  For test purposes, I have any packets going to the 192.138.5.0
subnet routed to sm0.  If I plug a speaker into the SoundBlaster output and
ping an IP on this subnet, I can hear the AX.25 AFSK 1200 packet tones.
(Cool!!)

However, I can't key the rig.  I built a transistor circuit based on Tom 
Sailer's suggestions.  I tested the circuit separately from the computer.  It
does, indeed, key the rig, so I know it works.  The soundmodem driver doesn't
seem to switch the RTS line on computer's serial port (/dev/ttyS0).  I stuck
an LED across this line to be sure the serial port worked.  If I do 
"echo hi > /dev/ttyS0", the LED lights briefly; so the serial port works.
If I ping an IP through sm0, the LED does NOT light at all.  Or it is happens
so fast I can't see it--a possibility--

Based on my understanding of the AX25-HOWTO, wrote a script to set up the
soundmodem driver on boot-up:

#!/bin/bash

setcrystal -s 0x220 -i 5 -d 1 -c 5
insmod hdlcdrv
insmod parport      # <--- is this really needed for the serial port keying?
insmod soundmodem mode="sbc:afsk1200" iobase=0x220 irq=5 dma=1
sethdlc -p -i sm0 mode sbc:afsk1200 iobase 0x220 irq 5 dma 1 serio 0x3f8
sethdlc -i sm0 -a txd 100 slot 50 ppersist 128 full
ifconfig sm0 hw ax25 kc2wz-2 up
axparms  -setcall sm0 kc2wz-2
ifconfig sm0 192.138.5.5 netmask 255.255.255.0 up
ifconfig sm0 broadcast 192.138.5.5 mtu 512
route add -net 192.138.5.0 netmask 255.255.255.0
exit 0

# end of script

Can anyone point me in the right direction what is wrong?  I'm pretty sure
the problem is software not hardware.  I'm probably overlooking something
stupidly simple.  I'd appreciate a pointer to what it is. :-)  Thanks for 
the help!

       73... bob, kc2wz
-- 
 bob billson        email: reb@bhive.dhs.org          ham: kc2wz       
                           reb@elbnet.com             Linux geek   /)  
 "Níl aon tinteán mar do thinteán féin."              beekeeper -8|||} 
        --Dorothy                                                  \)