In article <35aa85e9.429774@amadeus>,
	astaude@silas-1.cc.monash.edu.au (AS) writes:
> echo "ATZM1L2&D2%C1S0=2Q1" > /dev/tty00
> 
> doesn't seem to work. It just sits there and hangs...

Because the device isn't configured to use "local" mode it will block the
process until it detects a carrier. You should take a look at "man 5 ttys".

-- 
Matthias Scheler                                http://home.owl.de/~tron/