My first tune ever was made with protracker on ST ripping samples from nuke and 4mat ^_^

Sure, probably there are better ST trackers. Quartet is just the one that I remember trying from back then.

many good tunes were made on Quartet, but I wouldn't recommend it as the first sample tracker to look at on Atari in 2013. Maybe Hextracker as 4mat suggests or one of the variants of Protracker.

maxYMiser had software waveforms since version 1

Have you tried Hextracker?  You can vary the mix rate to get > 4 channels on stock machines.  (and STE dma support)

Whaaaat? That IS pretty decent. Didn't know a stock ST could pull that off!

The YM2149F has 3 channels that you can output a 4-bit logarithmic value on. The naive implementation would be 3 x 4-bit samples, yes, and if you didn't compensate for the log curve the samples would be pretty distorted.

However, it didn't have to sound bad/distorted, and it didn't have to be limited to 3 channels. You can instead do your mixing in software and use the channels as a single linked DAC, allowing more than just 3 channels and better sample quality. It requires a bit more clever programming, but the results are pretty decent.

There was a really decent sounding 4-channel tracker for the ST called Quartet. I think it's output was about equivalent to 8 bit / 16kHz. Example: https://www.youtube.com/watch?v=SPhcNthcweQ

Wasn't there some kind of trick on a bog standard ST where samples could be divided amongst the (three? four?) channels and played semi convincingly (read: screeching like a banshee chained into the pits of hell) with synthesis of some kind or other?

A few games had tracked music in their title screens:

After Burner: https://www.youtube.com/watch?v=Q0Av950xE8w#t=0m58s
Anarchy: https://www.youtube.com/watch?v=8xMZSrrMDOA#t=0m38s

I think this technique is just playing through the YM2149F with a timed interrupt, or just carefully timed code maybe. The STE had a PCM DMA add-on, but I can't think of any games offhand that used it. (STE was kind of unsupported game-wise, most developers still targeted ST I think.)

There were some sample trackers for the ST, so I'd guess there were sample chiptunes. But it needs to be investigated for sure!

EDIT: I was thinking that the STe has two DMA channels, but looking it up I found out that they have a very limited set of output frequencies. Not very good circumstances for these chip waveforms to "naturally" occur.

People who use these waveform samples on ST are mostly Protracker users ! (which is not exclusive to AtariST !)

The ST was an Atari. He's specifically asking about the usage of these types of sample on the Atari ST.

I've not seen a lot of this used in the Atari ST scene. I think often times there are more "valuable" sound that are used in the 2 digi channels. However, it actually sounds like a great idea to play with!

Because Amiga and NES.

And why is this in ATARI category???

lol @ "4mat style"

That's how we all did it back then And that's how I do a lot of my tones in klystrack too.