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+# beatmania DJMAIN Formats
+
+This document serves to explain the formats used on DJMAIN-based beatmania
+games from Konami.
+
+## About these formats
+
+The software for any version of these games consists of the ROM images and the
+HDD image. The ROM images store the program code, graphics and song metadata.
+The HDD image stores the charts and audio for each song.
+
+## In a nutshell
+
+TODO: Do something with the following:
+```
+BMFINAL
+
+Song metadata: 0x035444 @ 0x1E each
+  00-03: Song name offset
+  07-0D: Difficulties
+  0E-0F: HDD Song ID A
+  10-11: HDD Song ID B
+  12-13: HDD Song ID C
+
+Song metadata offset table: 0x03E06C
+```