Abstract: A converter system that allows a host system using a first interface to use a second storage using a second interface. The invention provides a method to allow an ECKD MVS DASD storage using an ESCON interface to be used by an open system using a SCSI-type interface without changes to the ESCON storage or the open storage interfaces. The method also permits the SCSI-type interfaced open system to be physically located greater than 25 meters from the ESCON storage system. The method involves mapping the SCSI-type interface data and commands into parameters used and understood by the ESCON storage. The invention may also be implemented to provide a digital data storage medium containing the method of the invention and a digital apparatus capable of executing the invention.