PRECI* provides a generalised architecture for a decentralised distributed database system capable of supporting a heterogeneous collection of pre-existing nodes. It permits data replication, subject to nodal access controls, and a number of user facilities, including both location-transparent and location-dependent queries in a relational language. A subset of these features, dealing with distributed queries in a decentralised environment, has been implemented using two homogeneous PRECI nodes within the same computer. This system is written in C under Unix, as described in this paper.