 Lee Felsenstein was one of the operators of Community Memory, the first public bulletin board system.Community Memory opened in 1973, running on a SDS 940 mainframe that was accessed through a Teletype Model 33, essentially a computer printer and keyboard, in a record store in Berkeley, California.The cost of running the system was untenable; the teletype normally cost $1,500 (their first example was donated from Tymeshare as junk), the modem another $300, and time on the SDS was expensive – in 1968 Tymshare charged $13 per hour ().