ChanServ changed the topic of ##yamahasynths to: Channel dedicated to questions and discussion of Yamaha FM Synthesizer internals and corresponding REing. Discussion of synthesis methods similar to the Yamaha line of chips, Sound Blasters + clones, PCM chips like RF5C68, and CD theory of operation are also on-topic. Channel logs: https://freenode.irclog.whitequark.org/~h~yamahasynths
<superctr>
Also, changing all '%' operators to '&' should incrase speed. Otherwise, especially when running without optimizations, you have to get the remainder of a division which takes forever
<superctr>
this video shows the edge cases, where the emulation differs from the real thing. and it's also 2 years old so there may have been improvements since
<superctr>
I'd say the situation is much worse with the OPX as every single patch sounds noticably different from the hardware recordings
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<andlabs>
oh commercial clones right =P
<myon98>
I think decapping OPS is significantly easier because it's just a ceramic package with a metal lid lol
<myon98>
Yeah with OPN2 reverse engineered I understand that OPN{,B} are mostly redundant
<myon98>
There's the OPNA/OPN3's stereo quirks but they're probably identical to OPM including the half-sample delay that comes from DAC SH)
<myon98>
I'm personally interested in OPNB because current OPNA emulators' ADPCM is a total guesstimate, but that's probably not important for most, might try nuking it myself if I finally get some free time
<superctr>
i think ADPCM emulation is fairly accurate now, at least for the algorithm itself
<superctr>
there is also a lowpass filter (for the ADPCM-B specifically but maybe ADPCM-A too) AFAIK that isn't fully understood yet
<andlabs>
also this person seems to have a serious problem with the DX7mk2
<andlabs>
or maybe it's just the giant emoji
<andlabs>
IDK
<andlabs>
*giant emoji biasing me
<myon98>
I don't believe there's an LPF for ADPCM-A, but I realized it for ADPCM-B too, thought it couldn't be more than some dumb averaging but I couldn't guess the exact algorithm at that time...
<myon98>
I was being inconsiderate when I said current ADPCM-B emulators are bad as a whole, sorry about that
<superctr>
it's very easy to do a digital IIR filter just using shifts and accumulators
<superctr>
no need to multiply
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<andlabs>
is there some button you need to press to cause a PC-98 to boot after it finishes its memory check?
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