Storage Module Device

A non-removable media variant family of 12, 24 and 48 MB capacity, the MMD, was then announced in 1976.

It was mainly implemented on disk drives used with mainframes and minicomputers and was later itself replaced by SCSI.

[3] By 1983 at least 25 manufacturers had supplied SMD drives,[4] including, Ampex, Century Data Systems, CDC, Fujitsu, Hitachi, Micropolis, Pertec, Priam, NEC and Toshiba.

For example on the GEC 4000 series minicomputers a configuration of 34 sectors of 512 data bytes each per track is used.

SMD disk packs (as the Storage Module itself was most commonly called) required head alignment to assure interchangeability of media between drives.