I remember when it was a big sotry, and Limbaugh was talking about it, but as for sources, I have only one that I just quickly searched on the Net (and it is not that great):
"Bill Cosby saying that AIDS was "started by human beings to get after certain people they don't like." "
http://www.grandconspiracy.com/synopsis.html
But, you could probably find more just by doing a "cosby aids" search. I remember in fact seeing it on the news here in NY (I think Fox5) when it came out.
I am in the middle of cooking dinner or I could probably search you out a better source. :P