The first public dial-up BBS was developed by Ward Christensen and Randy Suess. According to an early interview, when Chicago was snowed under during the Great Blizzard of 1978, the two began preliminary work on the Computerized Bulletin Board System, or CBBS. The system came into existence largely through a fortuitous combination of Christensen having a spare S-100 bus computer and an early Hayes internal modem, and Suess's insistence that the machine be placed at his house in Chicago where it would be a local phone call to millions of users. Christensen patterned the system after the cork board his local computer club used to post information like "need a ride". CBBS officially went online on 16 February 1978.[4] CBBS, which kept a count of callers, reportedly connected 253,301 callers before it was finally retired.