.sdat

An .sdat file is a music archive file in a Nintendo DS ROM. An sdat file may contain .sseq (sequence), .ssar (sequence archive), .sbnk (sound bank), .swar (wave archive), and .strm (stream) files.

File Specifications
For specifications on the sdat format, look at any of these pages:

kiwi.ds

emutalk

Programs to Edit .sdat Files
Tahaxan