Sunderland call him a right back, he's listed elsewhere as a midfielder. He is set for a 1 month deal with a possible extention is the initial period is successful.
Williams joined Sunderland from York City and was a regular during Sunderlands spell in the Premiership between 1999 and 2003.
He arrives in time for City's trip to Wolves on Saturday.
Good luck to Darren and welcome to Ninian Park.