Low End System Interconnect

The Low End System Interconnect (often given in DEC documentation as lowend system interconnect, or some other variant, but the acronym, LESI, is usual) is a DEC-standard bus used to connect mass storage devices to a device controller.

The LESI is a set of I/O conductors, instantiated as a 50-conductor flat cable (for long runs, this may be implemented as a shielded, round cable). Communication across it uses the Mass Storage Control Protocol.

Host interfacing is provided by the KLESI Low-End Storage Interconnect device controllers; controllers are available for the UNIBUS, the QBUS and the VAXBI bus.

Devices that use it include the RC25 disk drive and TU81 magtape drive.

External links

• EK-TUA81-TM_002 TU81/TA81 Technical Manual - the LESI is briefly described in Appendix A