Tiido wrote:It is fully OPL4 compatible as ar as sound generation stuff goes. CPU can be turned off and you can directly access the registers and make sound that way but the sample ROM is completely different beast without any similarity to YRW801 that most YMF278 things use.
That was a bit of an understatement, actually. Looking at the chart in the datasheet, not only is the sample ROM smaller, but they have stuffed more instruments in. The YRW801 includes only the standard drum bank, while this appears to have the usual nine of them. I strongly suspect that they must have made some significant compromises to get everything into half the space, much like they did for the standard InterWave ROM. If that's all you've ever heard, it may not seem to be lacking, but when you compare one with the other, the differences can be striking. That was the situation when switching between the 1 MiB InterWave ROM and it's 4 MiB counterpart. They are "based on the same sample data", but you start to really notice the shortened loops and truncated percussion once you've heard the larger version.
This still bothers me: if Fat-Seal certification is supposed to mean that the volume balance and instrument characteristics will be similar across GM devices, why is there such a dramatic difference between certified instrument banks? If we take the Audiotrix Pro (the very first Fat-certified card) demo files (not the 44-voice ones) and play them on your card, a Roland and the Fat-certified InterWave bank, the sound will still be quite different, in terms of balance, etc. What, then, was the point of the whole Fat certification exercise?