Yamaha ADPCM

• Microsoft Audio ID: 0x0020
• Extension: spb,mmf
• Company: Yamaha
• Sample: http://samples.mplayerhq.hu/A-codecs/format-0x20-laugh.mmf

A variant of this codec is used by several Yamaha chips:

• Y8950(MSX-SOUND)
• YM2608（OPNA) [the external ADPCM channel only]

and may also be used on the following chips:

• YM2610(OPNB) [the external ADPCM_B channel only?]
• YMZ263B(MMA)
• YMZ280B(PCMD8)

The functionality of this codec is explained fairly extensively in two datasheets:

• Y8950 application manual: http://www.datasheetarchive.com/pdf/download.php?id=212962c2fe1b63fdc5ab320ca05ff3efefc925&type=M&query=y-8950
• YM2608 datasheet (Japanese): http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J.PDF
• Translated version of YM2608 datasheet: http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J%20Translated.PDF