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Yes, the request is still very much open! Also, a complete forum styling would be even better.

Personally, I would very much like a "simplistic but elegant" black-and-white design. It doesn't necessarily need to be very retro, as some things discussed on here are pretty un-retro. But oh well, anything is better than what we currently have, I guess...

Btw finally changed the forum header text to something more concise. Hope you guys are ok with that

Hi mate, welcome back to the 1bit-forum

Nice examples! I think some people would indeed appreciate a proper xm21tm converter. It's not even terribly difficult to do. Check Shiru's engine packages or my github (for example this for some C++ resp. Perl examples of how to read out XM data. Also, I believe this is the most accurate XM file format specification. If you're interested let me know and I'll post a walkthrough in the tutorial thread.

Great to have these mods available as patches. Thanks a lot, mate.

Good job, thanks Frank!

Looks pretty damn stylish. Too bad it's "just" another FPGA box, but yeah, with that design even I am tempted

Huh? Who asked that where? Everybody knows that ZX Spectrum CPU is a TMS1000

So, what's the magic technique behind it? How are you interlacing the music with the graphics?

Was it this one, by any chance? Or was that for Savage?

In any case, retrieving the note table should be trivial. 25 bytes into the player there's a pointer to the music data, the note table is sitting directly before that address and is 54 bytes long.

Edit: Beepola 1.08.01, at offset 0x3a72c0

Hehe, seems you managed to post precisely at the moment when I moved my post to the "next gen engine ideas" thread

I'd suggest putting some 1 and 2 tick speeds in there as well. Some people are crazy for high speed Tritone abuse, and they're still sticking to the old XM converter precisely because those high speeds are inaccessible in Beepola.

Btw, would it be possible to apply your alternate SpecialFX note table as a patch, too? In combination with the Tritone speed patch it might make for a nice "FrankT's Modded Beepola" release...

Discovered a new trick while working on Houstontracker. Consider the usual pulse interleaving with variable duty cycle:

   add hl,de
   ld a,b          ;b = duty
   cp h
   sbc a,a
   out (#fe),a

   ;blabla same for 2nd channel

Now, as you know, we can add a "SID-style" duty cycle sweep by incrementing the duty when the add counter (HL) overflows.

   add hl,de
   ld a,b          ;b = duty
   adc a,0
   ld b,a
   cp h
   sbc a,a
   out (#fe),a

So far, so good. Now for the new stuff, we'll add an extra parameter that will be XORed against the duty setting on every sound loop iteration.

   add hl,de
   ld a,b          ;b = duty
   adc a,0
   xor c           ;c = additional XOR parameter
   ld b,a
   cp h
   sbc a,a
   out (#fe),a

This will produce some very interesting timbres! A primitive form of square wave FM, if you will. The result tends to have some aliasing noise (because the harmonics will cross the Nyquist limit if I understood this correctly), but I suppose it could be filtered out with the low-pass filter algorithm I was talking about earlier.

Now I actually went another step beyond this. Since I'm using a split timer update as usual, I have time to add an offset to the XOR paramter (C) every 256 sound loop iterations. Now this is a double sided sword - it will act nicely as a third FM OP, but only if the value is 1/256th of the base frequency used. When it is not, then the results will vary from "interesting" to "ouch my ears".

The attached .tap demonstrates both techniques. The first pattern starts with a simple duty cycle sweep and the additional XORing disabled, followed by XOR parameters of 8, $10, $20, $40, and $80. The second pattern starts again with regular duty cycle sweep and XOR 0. Following this, the XOR parameter is raised by 1/256th of the base frequncy once per 256 sound loop iterations, and following this the XOR parameter is raised by a fixed value (8 in this case) every 256th iteration. This is then repeated but with the initial XOR set to $80.

Don't ponder too much about the code in the .tap, there is some additional leftover stuff from an earlier experiment.
Anyway, I'm busy with HT at the moment, so if someone wants to pick up this trick in the meantime, be my guest

EDIT: Realized I posted this in the wrong thread, moved for clarity.