Musical potential of the NEXT.

[Alcoholics Anonymous]

It's an interesting idea. If he can go further and actually do some of it to verify size and practicality it would be even better.

[PiyoTaro]

"3xAY Turbo Sound" and 8bit-mono-PCM Sound by ZXNDMA with prescaler were confirmed as a sound generator.
*8 bit mono PCM sound by DA converter such as "Cheetah SpecDrum", "COVOX", "SounDrive" already implemented (PCM sound is realized by transferring data on the Z80 memory map to the 8-bit port by "ZXNDMA." The problem of "transfer speed being too fast" is solved by implementing "prescaler". However, since there is no "IM2 interrupt" function in other compatible machines, data transfer is only one time.)

The hardware implemented is like this.
Thread: TBBLUE IS NOW ON GITLAB! VERSION 1.0 MILESTONE REACHED!
https://www.specnext.com/forum/viewtopic.php?f=3&t=1283

Re: Picoblaze and Turbosound FM
The Z80N and the extra hardware is definitely not PicoBlaze. The FPGA is pretty much full. With a PicoBlaze you are able to fit a TurboSound-FM but what would you do with it? That doesn't mean that you cannot have a simple Z80 and a simpler spectrum AND a TurboSound-FM. It only means that on THIS particular combination; this will be impossible. Plus since the Next is a computer sold by a real company it cannot do things without licenses. The core team CANNOT release a Yamaha IP without a license FROM Yamaha otherwise the name may be revoked. This are very delicate situations and trust me nobody wants to get into these.
Independent users however may build their own cores with a combination of features not present on the actual Next. Nothing can stop YOU or some VHDL developer to realize whatever hardware they want that CAN fit on an SLX16.

Re: a volume mixer to both audio devices: There is such a request pending but Core 2 is pretty much done and this wasn't investigated
As for the accelerator card, the system is based now on I2C. Read the relevant documents in the doc folder of the distribution to see what can be achieved.

Re: PCM effects via the Pi.
This is possible from the user side using the Pi0 indeed

[PiyoTaro]

When I posted, his Github had FMSound firmware "JTx" present.

I tried speaking to the author of the core.
Original text is Spanish

cores de YM2203/YM2149/YM2610/YM2608/YM2151
http://www.zxuno.com/forum/viewtopic.ph ... 825#p25312
The Post by the jotego » the 12-Nov-2018, 21:53

I wanted to announce that now that the YM2612 (Megadrive) is ready and polished with JT12 , I added support for the YM2203 (used in arcades, FM Towns, PC88), also through the JT12. These two chips use the same core OPN called FM synthesis. But the YM2203 PSG sound also carries within YM2159, the same as the Atari ST. There is a core of this chip available but in VHDL, has the wrong volume table and wanted to try a few things. So I made my own version YM2149, called JT49 . Five years ago I made a version of PSG but do not recommend it . It was my first foray into this world and is a much improved core. That's why I made the JT49.

I'm in talks with Furrtek to include YM2610 (Neogeo also OPN series) in the JT12 and so the core of Neogeo who is preparing for Mister has sound. This will give a good boost to the core and virtually close the OPN series. The YM2610 is a YM2203 with PCM sound support so it will not cost me too much so.

So, if you want to use a core FM sound, you know. Yes, for licensing reasons, any core that use one of mine has to be open source.

Re: cores de YM2203/YM2149/YM2610/YM2608/YM2151
http://www.zxuno.com/forum/viewtopic.ph ... 825#p25317
The Post by the jotego » the 13-Nov-2018, 19:25

I wanted to adopt "TFM" as FM sound of "ZXSpectrumNext", I posted your blog and post of "JTx Core" on its official forum, but hope did not come true.

That's great. Just remember to release your sources along with your binaries if you use any of JTx cores.

By the way, "YM2159" in the article is correctly in YM2149 (SSG)?
(Actually, it is a fictitious device, there are additional elements such as stereo output or output duty ratio setting?)

Sorry, I meant YM2149. Too many numbers. YM2149 has a couple of features the original PSG from General Instruments lacked. It is also embedded into YM2203 and other parts.

[PiyoTaro]

(I do not know if it is official) I found "Uridium" MSX port.
In the theme song of the title screen, the music used in the original C64 version is used. It was exactly played with the sound of SID chips.
https://www.youtube.com/watch?v=0fOqhLlFCk4

Konami "SCC-I" is "Waveform memory Sound generator". "Waveform memory" is a small sampling data (8 bits, 32 bytes) of the output waveform "1 cycle" sentence is.
It is different from "synthesizer", it can not change timbre continuously. (Perhaps it has 5 channels of output, and it sounds a combination of several sounds.)

In a fictitious game console, "Waveform memory sound generator"(conforming to "SCC") is often used as a sound function.
It does not have a "noise generator" or "envelope" function, it has a lower function compared to "AY", but it has many sound channels.
https://www.msx.org/wiki/SCC

Additional notes.
DEMO.
Change "AY sound" to sawtooth wave of "SCC" with MSX
(Because the "MSX" system accesses external devices via the BIOS, you can set hooks and replace sound programs.)

• Reference site 「MSXのサウンドをSCCで鳴らしてみよう」http://www.tiny-yarou.com/sccplay.html
  (translation)Let's play MSX sound with SCC https://translate.google.co.jp/translat ... cplay.html

• [NandemoSCC]簡単な使い方 (simple usage) https://www.youtube.com/watch?v=UWZYxGFTchE
  [NandemoSCC]MSX2のYsのサウンドをSCCで鳴らしてみた (I tried sound of Ys of MSX 2 at SCC) https://www.youtube.com/watch?v=xvrVQzm8_LA
  [NandemoSCC]MSXのソフトのサウンドを片っ端からSCCで鳴らしてみた (I tried to sound MSX software sound from SCC at one end) https://www.youtube.com/watch?v=JFK6yp9GTgo

If the waveform of each "AY" output channel could be changed from a rectangular wave!
Example 1. It is possible to design the waveform of "one cycle" of the output waveform.
Example 2. "Low pass filter" can be applied to any of output channels ABC of AY. By continuously changing the "cutoff frequency", it is possible to do things like a synthesizer.

[PiyoTaro]

(I do not know if it is official) I found "Uridium" MSX port.

Konami "SCC-I" is "Waveform memory Sound generator". "Waveform memory" is a small sampling data (8 bits, 32 bytes) of the output waveform "1 cycle" sentence is.

"envelope" function, it has a lower function compared to "AY", but it has many sound channels.
https://www.msx.org/wiki/SCC

Additional notes.
DEMO.

If the waveform of each "AY" output channel could be changed from a rectangular wave!
Example 1. It is possible to design the waveform of "one cycle" of the output waveform.
Example 2. "Low pass filter" can be applied to any of output channels ABC of AY. By continuously changing the "cutoff frequency", it is possible to do things like a synthesizer.

Do not you think this extension is interesting?
Only the AY-3-8912 built in Spectrum, "output waveform can be designed" of 3 output channels

Konami's old arcade game was equipped with two channnel other sound chips besides AY.
Nintendo's "NES" also had a "bass" sound channel that not only produces a rectangular wave (which can change the duty ratio) but also "triangle wave" sounds.


Also, even if the output voltage can not be changed, if the "duty ratio" of the output waveform is changed from "50:50%" to "75:25%", "saw wave" will be obtained.
With this extension you can create distorted Guitar and Brass sounds and sounds like Strings with "harmonics like Bells".

Or, the reason for separating AY of "TS" from "built-in 8912".
Small expansion. I think that it is a clever proposal than adding external devices to the outside or making it "rewrite the FPGA for each application".
Set the extended function with the TBBlue config screen or the switch of the "ini" file of the system card. Enable to select "SAW" "SQUARE" output waveform of "built-in 8912".

[Alcoholics Anonymous]

You're not the first one to suggest enhancing the existing AYs

[PiyoTaro]

You're not the first one to suggest enhancing the existing AYs

About the implementation of FMSound of ZXSpectrum Next, the circuit size of "SID" was too large to be drowned. Also, it was an answer that "OPN software core" can not be adopted.
However, it seems that the development of the core is still continuing from the debate of the Official Facebook, so I would like to propose not only the Sprite but also the extension of the Music function.
Is there a small synthesizer core compared to SID or OPLL (or Konami VRC7)?
Since "AY-3-891x" has the upper bit of the register fixed to "0", I think that the function can be extended. I posted such a thing.

"Turbo sound", AY is adopted. Would it be possible to adopt the waveform memory sound?
Add 6ch * 32 samples = 192 waveform memories to the SAA 1099 like register map. I think that it may be possible to sacrifice "noise generator" and "hardware envelope function".

---
By the way, I have posted to this thread that it is.
'TSFM may be software emulation if you can output the sound of "Raspberry Pi Zero" accelerator board from the EAR terminal or HDMI terminal of ZXSpectrum Next board.'

p.s.
Currently, MML music tool "mucom88" with fmgen (as OPNA-YM2608 software emulator) as the core is talking about in Japan.

[Alcoholics Anonymous]

Since "AY-3-891x" has the upper bit of the register fixed to "0", I think that the function can be extended. I posted such a thing.
"Turbo sound", AY is adopted. Would it be possible to adopt the waveform memory sound?

The issues are always time and space but I'm hopeful something can be done.

There was a follow-up to the AY-8912 called the AY-8930 which is also seeing some attention in the MSX scene now:
http://www.vgmpf.com/Wiki/images/7/7c/A ... Manual.pdf

The main differences are individual envelopes for each voice, adjustable duty cycle and finer resolution for the counters. Adding a wavetable to that and maybe finer control over the duty cycles may be a good path to enhance the existing AY module without affecting size too much.

[Black_Cat]

Since "AY-3-891x" has the upper bit of the register fixed to "0", I think that the function can be extended. I posted such a thing.
"Turbo sound", AY is adopted. Would it be possible to adopt the waveform memory sound?

The issues are always time and space but I'm hopeful something can be done.

There was a follow-up to the AY-8912 called the AY-8930 which is also seeing some attention in the MSX scene now:
http://www.vgmpf.com/Wiki/images/7/7c/A ... Manual.pdf

The main differences are individual envelopes for each voice, adjustable duty cycle and finer resolution for the counters. Adding a wavetable to that and maybe finer control over the duty cycles may be a good path to enhance the existing AY module without affecting size too much.

Real AY8930 chip is software incompatible with AY-3-891x. The AY8930 does not have the ability to function as a DAC. The documentation for the AY8930 chip does not contain this information.

[Alcoholics Anonymous]

Real AY8930 chip is software incompatible with AY-3-891x. The AY8930 does not have the ability to function as a DAC. The documentation for the AY8930 chip does not contain this information.

It does mention that setting the tone period to 0 is equivalent to setting it to 1 so that method of behaving like a DAC won't work. Has anyone tried disabling a channel via register 7 to disable the tone oscillator instead? That might work.

It's not too important though because we don't have to copy incompatibilities and using a tone period of 0 to mean the oscillator is disabled (as on the 8912) shouldn't significantly impact 8930 compatibility.