GM ALDL interface

[Scott Feaver]

Has anyone used Peter Paul Fenske's circuit to interface with a GM ECM?  I
have built the circuit, but I am unable to get anything on my computer..
Maybe I'm doing something wrong..  The car I am using is a 91 Sunbird, it
has a 3.1L V6 engine with (I assume) the 730 ecm.  I am also using his comm
program that he wrote.  (Thanks Paul for all your efforts!)

Any help would be appriciated.

Scott