Designed and developed a CICS Interface system to facilitate migration from they’re existing in-house TP monitor and network to VTAM/CICS. The system operated between CICS and the applications, providing access to either network and both CICS and in- house files. This involved a message interface to translate maps between networks and a database interface to provide access using an in-house access method or CICS VSAM. An EXCP level task was written to provide the link between the in-house network and CICS. All interfaces were transparent to the applications so that migration could be accomplished without extensive changes to the application logic.