furnace/doc/7-systems/msm6258.md

OKI MSM6258

a single-channel ADPCM sound source developed by OKI. it allows max sample rate of 15.6 KHz... with no variable pitch. most prominent use of this chip was Sharp X68000 computer, where it was paired with Yamaha YM2151. Furnace's implementation is MSM6258V, a CPU driven variant that is unlimited by amount of sample data, being able to to be fed from the system's RAM.

effects

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config flags

chip clock rates

MSM258 is an extremely basic ADPCM sound codec. it has no variable frequency rate, it depends on clock rate of a chip itself. Furnace supports following rates:

• 4 MHz, resulting sample rate is 7812 Hz
• 4.096 MHz, resulting sample rate is 8000 Hz
• 8 MHz, resulting sample rate is 15625 Hz (used in Sharp X68000)
• 8.192 MHz, resulting sample rate is 16000 Hz