Heh - I just did something similar with a new, unused Subway USB interface... connected it to my A600 clockport adapter - pin 1 wasn't labelled, so I "guessed", based on how the cable would have had to bend awkwardly if connected the other way.
Needless to say, I got it wrong, and *pop* - no more Subway :-(
I then looked online, and found the instructions that I needed, which would have avoided the damage.
*sigh*
At least OS3.1 ROMs aren't *too* expensive, in the grand scheme of things... :-)