Synthesizer Demo

[DusanStrakl]

I wrote couple of tutorials on how to use ROM functions to program AY2151. As result I also wrote a demo for it in form of simple synth.



I link full source code from my blog:
https://www.8bitcoding.com/p/sound-in-a ... g-rom.html
https://www.8bitcoding.com/p/sound-in-a ... write.html

You can also try it here: Try It Now!

[Xiphod]

Very nice!

On my X16's screen/hardware, the letters on the white keys don't show up. They work fine, just I only realized they were even there because of your screenshot. The keys on the black keys are visible fine, just not on the white keys (for me at least).


Now add a record/playback button [ I took a stab at that in my own synth, it's a bit harder than it seems; in terms of recording the note/duration sequence actually played, not just some kind of WAV recording ]

[Xiphod]

Wow, and something I just noticed: with the (expensive) WASD Keyboard, I can press all the keys I want for the Synth.

But on the standard Perixx keyboard, I can only press a few different key combinations.

And this is also the case in my own VSynth. It's something I never noticed before - thought was an SMC issue/limitation?

Anyway, neat, I can fully Synth with the WASD Keyboard

[DragWx]

Wow, and something I just noticed: with the (expensive) WASD Keyboard, I can type all the keys I want for the Synth.

But on the standard Perixx keyboard, I can only press a few different key combinations.

You're encountering Key Rollover. The WASD keyboard has N-Key rollover, and the Perixx keyboard does not.

[DusanStrakl]

Very nice!

On my X16's screen/hardware, the letters on the white keys don't show up. They work fine, just I only realized they were even there because of your screenshot. The keys on the black keys are visible fine, just not on the white keys (for me at least).


Now add a record/playback button [ I took a stab at that in my own synth, it's a bit harder than it seems; in terms of recording the note/duration sequence actually played, not just some kind of WAV recording ]

Good to know. I will use slightly darker gray for letters on white keys for next build.

Yes, I was thinking about recording functionality. It is definitely doable but require some more time. I was also thinking about adding some background base/drum rhythms or metronome. Then another thing could be adding PSG support for additional 16 channels, looping feature, etc. but then we are already in full blown tracker territory

[DusanStrakl]

Wow, and something I just noticed: with the (expensive) WASD Keyboard, I can type all the keys I want for the Synth.

But on the standard Perixx keyboard, I can only press a few different key combinations.

You're encountering Key Rollover. The WASD keyboard has N-Key rollover, and the Perixx keyboard does not.

Interesting. I was not familiar with this and I only tested on emulator, need to get my machine from the closet. I also have both keyboards to test with.

If I understand correctly, this problem is caused by hardware fault and there is no workaround to fix it in software.

[DragWx]

If I understand correctly, this problem is caused by hardware fault and there is no workaround to fix it in software.

Correct, it's a side-effect of how the keyboard's circuitry is designed, and there's no real software workaround other than allowing users to redefine keys if there's a particular combo their keyboard struggles with. And of course, the hardware workaround is to get a keyboard with N-Key rollover, but those are usually higher end.

[DusanStrakl]

On my X16's screen/hardware, the letters on the white keys don't show up. They work fine, just I only realized they were even there because of your screenshot. The keys on the black keys are visible fine, just not on the white keys (for me at least).

I just uploaded updated version with letter on white keys one shade darker. I want them to be subtle but obviously they need to be visible. I hope it looks better now.

[Xiphod]

This is so polished and enjoyable to use! Especially I like the little "channel" lights.


One reason I'd like a key-stroke recording is so that sequence can be used to play a composition back (in terms of notes) - which should be smaller (more compact) than an actual digitized audio recording (like in terms of one of the PLAY commands in BASIC, or just in sending note/tempo instructions to the chip). But I see it's surprisingly hard, as those key-strokes don't (generally) fall into "normal" rhythms (except maybe for very well trained musicians?).

Another Someday-Project is resurrecting 3DO CPU Bach - and its concept of generative music (Sid Meier wrote an extensive whitepaper on his approach). Or another tangent - I reinstalled WinXP recently for some unrelated project, and I found more audio samples as part of its installer, and was reminded of the "generative imagery' that old Microsoft Media Player had when playing WAVs.