I've recently been trying to get AY/YM music playing on the SID chip. (for my own amusement)  Using data from the old YM format by Leonard/Oxygene, I'm streaming compressed register output in real-time to give a fairly ok sounding simulation of the AY.

Here are some examples of Atari ST music.  My pre-processor does frequency and volume conversion, and using the Exomizer compressor most tracks export out to a 4-40kb size depending on complexity. (rather than song length)

Mad Max - "There aren't any sheep in Mongolia"

Tao - "Toxygen"

Scavenger - "DBA Intro 6"

There were, obviously, some caveats to getting them working on the sid:

The SID chip doesn't like jumping around the volume range per frame, I've got somewhat around this by doing a bit of ADSR banging and resetting the gate for a few cycles.  AY envelope support is quite minimal at the moment, so some tracks don't quite fade how they would on the hardware.

There is basic 'buzzer' support (using the saw wave) but while it does frequency it doesn't take the envelope shape into account or mix the existing tone signal.  So, currently, tracks like the "TCB Bobs Record" screen have quite a flat bass sound.

The AY chip has the ability to mix both tone & noise simultaneouosly on the same channel, to get around this I alternate noise/tone per frame when that's enabled.

SID-wave support is currently on/off based on if the timers are active, rather than calculating frequency and determining the channel from there.

I had some digi drum stuff working but it uses the 6581 volume channel trick, so currently only works on those chips.

Last edited by 4mat (Mar 12, 2016 2:46 pm)

Oh wow, this SID can do SIDsound... ermmm... heehee

Nice work, looking forward to the final release. I take it this will be more accurate than the good ol' YM-64, then?

Amazeballs in awesomesauce!

This is really nice !!!
I just wish to see sndh supports with all the ST tricks to see how the SID will emulate itself lol !

oh man, would love to try.
sounds amazing.

Added support for .VGM format PSG files.  (Master System, Game Gear, BBC Micro etc)

The noise channel currently shares with one of the tone channels but could be moved to a sample channel instead.

and now a wrapper for plus/4 (ted) sound emulation:

Job well done!
On the risk of sounding stupid, what's that song? Somehow I can never find any good TED musix but this one is lovely...

thanks, it's out of this

More WIP projects : live sid remixing tool.  Here mixing Zabutom/Dubmood's "One little wish" with Rob Hubbard's "Delta" across 2 sid chips. (1-3 chips are useable)  All playback is buffered so each song's channel routing can be changed around, songs can be time-streched and delay fx are possible.

Oh holy shit, that's awesome.

Blimey - that's very cool!


hahaha, it's LE AWESOME big_smile

Playing a Knaeckertraecker demo tune through the TED soundchip wrapper.   These tracks are a really good test-bed.  (this one plays a 4x per frame)

Today's little WIP is realtime side-chaining random sid tunes while they play.

Track is by Jeff/Camelot.  Like a normal side-chain setup once the selected channel goes over the detection threshold the other channels have the ducking applied.  In this case channel 3's bass drum is the loudest instrument and it affects channels 1+2.   Only a release envelope is simulated here so it doesn't always work.    When the border timer is flashing it's enabled.