Turbochip - 7-channel YM+DMA replay

[junosix]

Not sure if this ought to go into the YM or Digital subforum because it's a bit of both. I've started work on a 7-channel sound routine that uses DMA audio to play 3 channels of 256-byte wavetable data with variable pitch and 1-channel of fixed-pitch full-size samples (for drums and that) alongside 3 channels of YM notes inc. noise. Aim is to have a sort of PC Engine or Konami SCC chip sound to it, should end up using around the same CPU use as .mod replay but the memory footprint is a lot smaller, also it uses none of the timers. More to do but thought I'd stick up what I've got going so far - .mp3 and .tos executable attached (Bit of a crap test pattern but it serves its purpose for now. Press Space when finished to do... absolutely nothing! You'll need to reboot)

[ggn]

Nice project!

Since this resonates a bit with what I've recently done, perhaps you could use Arkos tracker 2 for the YM part?

[junosix]

I spotted the Arkos stuff as I was working on this and wondered the same! Haven't checked it out yet but it would be cool to use it, at the moment I'm coping with creating pattern data as blocks of dc.b but that's going to be a pain before too long and I'm not savouring the thought of having to write an editor just yet.

[matt]

Nice work!

[dma]

Wah, that's a pretty wonderful concept, great idea and work so far junosix!
I'd be love to test it, once an editor can be used to.

(maybe this DMA synth engine could be added to maxYMiser? but not sure gwEm got time for coding on it now tho)

[bear]

So cool! Hope to hear more soon!

[FedePede04]

i have also add DMA drums to my Editor/Player, so it is now 3 YM and 2 Channels drums.....

Not David Whittaker version, but heavy inspireret by it

Enduro Intro Music.mp3

[junosix]

Cheers guys! Looking forward to hearing what it's capable of in the hands of the talented Atari chip musicians Wouldn't imagine it's an easy case of dropping support for additional channels into existing editors so I'll need to spin one of my own at some point.

FedePede, that Enduro music sounds excellent!

[Frank B]

That's really cool!

[metalages]

Before going on this prototype http://cyber.savina.net/sound/sound.htm I have tried to figure out how to work in a cheap way with wave table.

I had the feeling would be possible to have something rather cheap on 2 channels : 1 for wavetable, 1 for drum
- use looping DMA buffer set with the length of the transposed wave
- fill the other channel non stop with a dma looping interupt (for drum)

Playing with wavetables is really interesting. Cool project

[junosix]

You're right, wavetable stuff is pretty fascinating. The way I'm mixing is with the usual approach of writing 500 double-buffered bytes and switching/restarting DMA per VBL, using a scale table for the tuned channels and incrementally stepping through the PCM data for the drums. Going with the approach that the NEC and Konami chips use, they have a 32 step wavetable. I repeat a 32 step waveform throughout 256 bytes, initially as a cheap way of avoiding having to mask off a step counter during mixing at the expense of some memory, but I then realised I could use the extra space to get some effects like PWM for free. I'm also interested in seeing if I can get some "true" wavetable synthesis (as per the PPG Wave synth) by switching waveforms mid-read, if that makes any sense!

[metalages]

https://www.youtube.com/watch?v=YvrJTmIPSrI

[MiggyMog]

nice work. it is a shame that the st never got the AMY chip, this would have been awesome

[junosix]

Nemesis "Challenger" theme cover.

[matt]

amazing work.

[dhedberg]

Woo... like the sound of that!

[FedePede04]

sound great.. keep up the good work

[MiggyMog]

Nice work Junosix, sounds very SCC like.

[lotek_style]

Tao has done this ages ago... nice to see somebody else taking the task

[evil]

Indeed, Taos "Magic Synth 4.0" have three channels YM (with all his usual YM tricks) and three voices DMA-synth to form 6-channel chip tunes.

I've recorded two test songs that I got:
Stella Polaris: https://www.dropbox.com/s/fuyjtkphjxpkl ... o.mp3?dl=0
Waveshaper: https://www.dropbox.com/s/z5f23fsyrzglj ... o.mp3?dl=0

You might know Stella Polaris from a couple of STe demos; It was first used in "..do things" in 1999, in form of a three channel DMA-synth. Then used as a pure YM2149 version in the reset demo of "Madness" later that year. Both demos by Cream.

Here are those original versions:
DMA-synth: https://www.dropbox.com/s/ijm3vpmjrruxb ... h.mp3?dl=0
YM2149: https://www.dropbox.com/s/po86v6686z75c ... 9.mp3?dl=0

I think the fidelity of Taos DMA-synth is really good and as we all know his YM-stuff is second to none.

[Cyprian]

Indeed, Taos "Magic Synth 4.0" have three channels YM (with all his usual YM tricks) and three voices DMA-synth to form 6-channel chip tunes.

it sounds very good. Which editor was used?

[MiggyMog]

There is a third of these tunes on cream site http://creamhq.de/downloads.php?action=taosongs

[evil]

Indeed, Taos "Magic Synth 4.0" have three channels YM (with all his usual YM tricks) and three voices DMA-synth to form 6-channel chip tunes.

it sounds very good. Which editor was used?

Magic Synth 4.0

[Cyprian]

Indeed, Taos "Magic Synth 4.0" have three channels YM (with all his usual YM tricks) and three voices DMA-synth to form 6-channel chip tunes.

it sounds very good. Which editor was used?

Magic Synth 4.0

never published I guess

[evil]

it sounds very good. Which editor was used?

Magic Synth 4.0

never published I guess

That's correct, Magic Synth 2.5 is available but it's without any DMA-synth.
https://demozoo.org/productions/65436/

Anyway sorry for hijacking the thread.