LazloPsylus wrote:

Just making sure. As a guy working on a sound driver (or three) and enjoys doing research on the MD and co., I've been more than a little surprised at how few people are even remotely familiar with the YM2612's timers, so I'm glad you're familiar with them and at least made an informed design decision.

I'll probably chime in again if I find something useful to contribute. Otherwise, good luck on your project.

Thanks smile I had to dig into YM2612 Timers for The FMDrive Vsti witch features CSM mode "speech synthesis control" ^_^
PM me  what you are working on unless it is top secret smile


Of course I will add that you can also write to the volume register at CPU speed without using Hblank timing.
Writing this sequence of data for a 16 data point sinewave,
.db 04,02,01,00,00,01,02,04,11,13,14,15,15,14,13,11
gave me something like 1978Hz without any wait...
this gives us roughly a 31,648 KHz sample rate, it should be the same thing for PWM or PCM sample reading...assuming there isn't any other code going round then the audio stuff.
So it is twice as fast as Hblank with near 32µs against 64µs
the simplest square wave could be .db 00,15 as high as 15824Hz
anyway at high rate things get screwed up easily smile


SID sound...Timer modulation implemented on SN76489 MIDI board & in SPSG VST >> … ded-synth/
The idea is to enhance the variety of sound, producing tones that the chip normally cannot produce to make some cool music!

Compatible with the SN76489 (code heavily modified!) open source arduino code by Littlescale smile
The code will be available for free of course to anybody wanting to mess around.
When use in conjunction with the MIDI device, SPSG vst will act as a controller with volume/pitch envelope generator and table! smile smile smile


Jelly Stone park, MD USA

MAN, you da best! Really going to have to add the SN76489 'synth' to my to-do list!!

Philadelphia, PA

I've spent the past few hours playing with the VST. I'm really impressed! This thing is insane. The custom timer stuff is just mind blowing. It uses chip emulation as a baseline, gets that perfect, and then adds things that wouldn't be possible without a DAW. It's a big contrast to the Plogue Chipsounds "jack of all trades, master of none" approach.


This looks really cool! I just got FMDRIVE but I may have to pick this up sometime soon as well. Thanks for the great Sega VST's!


SPSG VST SID effect >> MIDI >> VGM  proof of concept...!
Here we go, this is a quick test with the PSG clocked at 1Mhz, only one channel and SID modulation..
you never got an SN76489 vgm with that smile
the greatest accuracy for exporting a midi file with the SPSG modulation as been made through Reaper at 22050 PPQN.