The TRIUMF control system is based upon a single, 35-crate parallel CAMAC system, access to which is shared by several small computers. This concept has recently been extended to include a 'data interface' computer which serves as a message organizer between several small data acquisition systems, the control system, and the IBM 370 at the University of British Columbia computing centre. The data interface uses a Data General Eclipse S200 minicomputer with memory mapping. The TRIUMF experience of multisourcing a large CAMAC system is discussed. Preliminary specifications for a module and protocol for crate-to-crate CAMAC communications are described, as are plans for the implementation of a 9600-baud SDLC link between the data interface and the IBM 370. The design of an asynchronous line multiplexer, which interleaves seven user channels onto one 9600-baud trunk, is presented.