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Haha, no, I can't take any credit for that discovery, you figured that out by yourself!

I've done some experimenting with using bit 3 for reverb. However, volume levels for bit 3 vary considerably between 48K board revisions (not to mention different models), so it's not really useful. Generally speaking, the output from bit 3 is low enough that it can be ignored for practical purposes. (It does cause problems for engines with a high volume resolution, but that's another story.) Anyway, the main reason you'll see bit 3 being used is because it costs additional cycles to mask it out. Povver is a typical example of this: Use of bit 3 is by no means intentional, but there is at least one location where I couldn't find enough cycles to mask it. Aside from that, some PFM-based engines use bit 3 in sync with bit 4 for a little extra volume boost. Alone Coder's BeepTracker engines do this, for example.

It's totally unclear to me what's going on here. Let's wait for Noel.

Ah, crap. Here you go.

I see. Very strange indeed. Yes, sounds like it's running in contended RAM, but then it seems to run at pretty much the same speed as the 48K version!?! Well, let's first rule out contention issues. Could you export an .asm file from 1tracker, and post it here? (Or, if you want, assemble it yourself at 0xc000 and try it out. 1tracker's asm output works with sjasmplus.)

Also, have you tried with any other engines?

The problem on Speccy isn't so much one of finding some free cycles to update graphics. In fact, in PFM and Phaser type engines, you can actually waste quite a few cycles with barely any drawbacks. However, on Speccy we have this thing called memory contention. Very simply said, if you write to or read from certain memory locations on the Speccy, additional wait states will be introduced. While it is possible to predict when those wait states occur, actually writing an engine that will work around these limitations is extremely challenging, so basically nobody bothers. AMP16 is currently about as good as it gets when it comes to running 1-bit code in contended memory.

Watcha mean, the gerber files won't download? You can't download them from github?
Just grab https://github.com/utz82/HoustonTracker … master.zip and it should have all the stuff.

Don't install TI-Connect and TiLP at the same time, that's not going to work.
Unless you are using a TI-82, you can theoretically just use TI-Connect, though I faintly recall someone reporting problems with TI-Connect screwing up the HT2.*p files. I'd say give that a try first though.

Awesome, thanks for the hard work and the great write-up, Shiru. And not least congrats on composing such a kick-ass tune.

I faintly remember trying to code something for GTIA some years ago and also being frustrated by the not-so-stellar documentation available. I wonder if there are any GTIA-specific tricks one could pull here. The basic mode of operation is to write a value < 8 to 0xd01f to set the beeper on, else it's off, right? Did you discover anything beyond that?

I'm sorry, but I won't make it. Too much stuff going on right now.

Thanks for the reminder! Would have totally forgotten about it, since normally SV happens towards the end of the year.
I'm tempted to join this and maybe also 2600 msx, but I'm not sure I'll have time to make something.

Great to see some in-game 1-bit music action, and also great to see the MZ-700 getting some love! Tbh I think it actually sounds surprisingly decent considering the sample rate.

There are some people on here that know more about 8253 wizardry than me, but a quick couple of thoughts:

- Beware of the Nyquist limit, ie. the highest frequency in the audio may at most be half of the sample rate. So if you replay at ~2Khz, you should apply a low-pass filter with a cutoff of ~1KHz before resampling.
- pcm2pwm isn't very well suited for harmonic content. Its main purpose is to encode percussive sounds in a very size-efficient manner.
- I'm not sure intersective PWM is worth it. In order to produce decent results, it requires a very high sample rate (likely at least 80KHz), which would be pretty hard to pull off on a 3.5MHz Z80 machine.
- It is possible to mix multiple channels without volume control. A method that works well at low sample rates is to have 2-4 pulse wave generators with a duty cycle below ~25%, and OR their outputs together (example).

Anyway, thanks for the detailed write-up, looking forward to hearing more from your 1-bit endeavours!