Also known as Sam Disk Interface or SDI it was one of the original peripherals produced by MGT
at launch time and it allowed users with a ZX Spectrum
and PLUSD/DISCiPLE interfaces (previous MGT products) to re-use their Shugart 400 type 5.25” or 3.5” disc drives with the Coupé without having to purchase the internal units.
It also featured the same parallel interface as the Comms Interface
allowing the users’ printers to be accomodated.
It came with instructions and an “SDI loader” on cassette.