Over the last 5 years, Asaca Corp. has developed a multibeam, magneto-optical disk drive with native 12.24 MByte/second transfer rate. Originally developed for video broadcasting, it is now being adapted for the computer mass data storage market. A SCSI-2 interface is currently being developed to attach the drive and its related autochanger to a high-performance computer as components of a network-attached, hierarchical file server (HFS) system. Storage capacities of 2.88 TB, and average aggregate (four drive system) I/O speeds of 32 MB/second are considered possible. Asaca's High-Speed Magneto-Optical (HSMO) technology enables a re-definition of the present storage hierarchy by allowing the use of optical disks to complement or, in some cases, replace high-performance magnetic tape. Many of the HSMO performance figures quoted in this paper are estimates which will be confirmed in the very near future when the SCSI-2 interface is completed.