S98

Sound 98
Developer:
Header:	Custom
Content:	Log
Instruments:	Combined
Target Output
Released:	c. 2004
First Game:	N/A
Extensions	*.s98

The Sound 98 format (the name is a guess, though it was probably named after the PC-9801) is a log of the instructions sent to several Yamaha sound chips used in various Japanese home computers like the NEC PC-6001, PC-6601, PC-8801, and PC-9801, the Sharp X1, and the Fujitsu FM-7 and FM Towns. Playback occurs by emulating the audio chips used by these computers (the YM3526, YM2151, YM2203, and YM2608) and outputting the generated signal to a speaker. While this technique could potentially be used for any device using one of these chips, the community seems to have limited their efforts to the Japanese PCs.

While this method bypasses having to emulate the countless custom methods that have been developed over the years for storing and playing video game music, it is not without its share of problems. Only the processed data is recorded, not the original files and code. This means that it is not possible to easily edit the music once it is recorded. It also means that each song must be timed by hand since the audio chip never sees the actual start and stop of looping music. For this reason, many S98s can have timing errors.

Players

(Category)

• Audio Overload - Linux, Macintosh, Windows
• S98 Input - foobar2000

Editors

(Category)

Converters

(Category)

S98 to ?

• Audio Overload - Linux, Macintosh, Windows - WAV

Games

(Category)

Any game released for the PC-6001, PC-6601, PC-8801, PC-9801, and FM-7 can have the Yamaha FM Synthesis portion of their soundtrack logged to S98 format.

How to Obtain

Logging S98 music isn't too difficult, and can be done with various emulators, but it does require you to be familiar enough with the game you're logging to know how to get each song to play so it can be logged. Many of the more popular games have already had their soundtracks logged to S98 format and can be downloaded from these links:

• s98.joshw.info - Josh W (individually 7Z archived, most with proper timing).
• zophar.net/music/s98.html - Zophar's S98 archive.

Technical

Chips

Chip	Manufacturer	Devices
YM3526 (OPL)	Yamaha	Sound Expander, 35+ arcade games.
YM2151 (OPM)	Yamaha	X68000, many arcade games.
YM2203 (OPN)	Yamaha	PC-8801, PC-9801, PC-9801-23K, some arcade games.
YM2608 (OPNA)	Yamaha	PC-8801, PC-9801, PC-8801-23, PC-9801-86, some arcade games.

Links

• smspower.org/Music/VGMFileFormat - Official Specs.
• en.wikipedia.org/wiki/VGM_%28file_format%29 - Wikipedia.