So, you're basically doing some kind of AM? Isn't this quite heavy on the CPU to update these wave forms all the time?
The modulation for the guitar sound kinda like FM where amplitude of one wave (carrier) is transposed to an offset (0-31) for readout of another wave form (modulator). But it works at 60Hz (on ISR) so nowhere near frequency domain.
Regarding CPU, the ritme guitar sound is a stack of 4 effects: interference > chorus > modulation > gain > out. note I given them names but they might not actually reflect the real thing. Each of these effects have an (z80) T-state count on average 90 (some guess out top of my head) per byte, so 90 x 32 = 2900 T states for 1 and for 4 this becomes like 11500 per channel. So doing on the fly is quite heavy indeed. Once pre-computed it is only 5 x 32 = 160 bytes update (roughly 3000 cycles) per frame for all wave forms if updated all at once, or 9.6 kb per second like ARTRAG mentioned.
Anyway, if you define binary format for exchanging wave file, it could be fun to use it to export speech samples from my voice encoder and import them in your replayer, to be modulated as instruments.
I thought a bit about longer samples (like converting them from PC or so), but unfortunately the way it is setup now it is not easy to implement, besides we have OPL4 for that 
. Perhaps it could be revisited in the future.
Hmm.. This stuff is suitable for some Tim Follin as well, yes? 
...undoubtedly he would have brought this to a hole other level if Konami hired him at the time ...
Can you upload music that can be played on a real MSX please? I'm really curious to hear this on my MSX.
How? I have not even started on the stand alone re-player yet
Other than that I made great progress today! I've just implemented the tempo channel, so it is now possible to alter the tempo mid song 
, how cray is that! Still lots of other things to do though.
Hey Ghost, this is exactly the kind of topic's I keep double taps on. As a coder I've written a few, as a dreamer I did hundreds of'm. I love building trackers. Interesting to see one build on extended graphics cards, that's new. The vid show smooth screens, love it. Love the fiddling with instruments/waveforms too. Doing real-time register updates makes new possibilities. No borders, just free thinking.
Good one, mate. I'll be checking in frequently
Anyway, if you define binary format for exchanging wave file, it could be fun to use it to export speech samples from my voice encoder and import them in your replayer, to be modulated as instruments.
I thought a bit about longer samples (like converting them from PC or so), but unfortunately the way it is setup now it is not easy to implement, besides we have OPL4 for that . Perhaps it could be revisited in the future.
Just a thought, in the replayer, once you have to precompute all the effects applied to the wave samples, you end to play, on each channel, a sequence of 32 samples per frame taken from ram as they are. All the real time processing will limited be on periods and volumes (according to notes and to other effects).
It should be relatively easy to load the sequence of 32 samples with their periods from an external source, e.g. a voce encoder, rather than from the tracker ...