ECU is the Extended Communiction Utility. I use to use this 
program all the time when I did not have an internet connection
to do zmodem because zmodem was a built in protocol of ecu.

To install the program it should be easy:

gunzip ecu330.x86sol.tar.gz
tar xvf ecu330.x86sol.tar
cd ecu330
make install

Note: I did not get a chance to test this program out at all.
The executables will install in /usr/local/bin and the 
lib/config files install in /usr/local/lib/ecu if I remember 
correctly.

You will need the two programs 'gunzip' and 'make'.  The gnu
make should be available, some sites label it as gmake.

Good luck hope it works.
Someone drop me an email if they get it running:

palowoda@fiver.sns.com

---Bob Palowoda