SCSI
SCSI (short for Small Computer System Interface) was a standard interface published by ANSI in 1986.
In the context of making electronic music in the 1980s and 1990s, it was chiefly used by samplers to talk to storage devices such as hard drives and CD-ROM drives, to store tens or hundreds of megabytes of samples, and load and save them faster than a 3.5" floppy disk drive could, let alone SysEx messages over MIDI.
A SCSI bus supports up to eight devices, including the host itself and up to seven peripherals.
Example implementations
Studio infrastructure: ACSI | DCB | Eurorack | MIDI | SCSI | Tracks and channels