|FM 4op. with SSG/PCM||SSG||PCM||unidentified|
|YMF274 (OPL3 compatible)|
|YMF282 (OPL3 compatible)|
|YMF286-K (OPNB compatible?)|
|YMF297 (OPN3-L + OPL3)|
* From early 1980s, Yamaha has developed sound related chips in four digit
numbers (YMxxxx). However, in early 1990s it seems to have reached the end of
numbers: YM9xxx. Maybe this is the reason Yamaha initialized their product as Y
+ two identifiers + three digits.
* At least in the range of 2xx, YMF seems to mean FM, and YMZ seems to mean non-FM. However, I guess they were developed in the same line because of the following reasons: 1) their numbers are close but aren't overlapped. 2) They had been produced in close numbers also in the days of YMxxxx. In any case I mixed them on this chart.
* An obvious difference from YMxxxx numbers is that DAC and sound effect chips were separated to other lines. And in YMF/YMZ range it's difficult to find classifying policies of OPM/OPL/OPN etc. in certain range of numbers.
* OPN compatibles have ended at 2xx range. But others continue to 7xx numbers.