On the back of the Sega Dreamcast Development Box, there are SCSI 1 & SCSI 2 ports. The SCSI 1 links to the HKT-0400 - GD-Writer, while the SCSI 2 links to the Sound Box. The Sound Box could also be linked to the Apple Power Macintosh PowerPC 6500/225.

The Sound Box uses a MIDI In/Out and Audio Out interface, and is mainly used for MIDI sound production.