Things needed to help create a ZX81 AY interface

[BrunoFlorindo]

Now that I've found that it's possible to create a new AY interface for the ZX81*, I would like to request an example of how to send music to it. If the interface becomes a reality it will use the same AY ports used in 128K Spectrums or 48K Spectrums with the Zaxxon AY-Magic interface.

So, let's suppose I want to assemble a small routine that will send sound or a tune to the AY interface. The ports are the same as in the 128K Spectrum. What should be kept in mind when composing music for it? Can someone post an example? I understand that even though the ports are the same, assembly listings created for the 128K Spectrum or 48K with AY interface won't sound right because of the different Z80 speed, but I need an example. The interface will be made to sound as much as the 128K AY as possible.

So, these are some of the things that I think we'll need if we really want to make this happen.

-Examples of AY music in assembler, or in BASIC with machine code in REM lines.
-Simple ZX81 tracker which outputs a binary block of code, with or without the playback routine, with instructions on how to use it.
-A way of using currently available trackers to create tunes for the ZX81. Maybe PC trackers allow customization of timing and type of output? Or maybe Spectrum trackers can be modified.
-Ideas and suggestions

If someone's wondering why we're doing this instead of using exploring the Zon X-81, it's simple:

-There's a huge culture around 8-bit AY music and when we speak of ZX Spectrum tunes there's a lot of good stuff. How many AY tunes for the ZX81 do you have? 3, 4?
-There are many AY composers who are active and once they know the ZX81 can do it (in emulator and on the real thing) they might include it. And their work will inspire others.
-The new AY interface will probably have a jumper to select between Spectrum AY ports or Zon X-81 ports. This should make everyone happy.
-Adapting ZX Spectrum AY music to the ZX81 might be easier than having to do everything from scratch. We already know that the AY format cannot be converted because it's tied to the machine that it was written for, but those who use trackers will probably find it easy to adapt.

My friend can help me with the hardware part, but we need your help. Help us make this come true.





*Zx81, TS1000, TS1500 and clones with compatible edge connector / backplane.

[gus]

Hi Bruno,
I reply to your post on speccy.org and like I already say I can help with that
I think that Xavsnap can eventually (and I can help too) include support for the new sound car card on his emulator

Gus

[yerzmyey]

The interface will be made to sound as much as the 128K AY as possible.

I'm not entirely sure what do You mean by that.
The interface already does because AY/YM does.

So probably You mean tunnning as close to ZX128 as possible.

But keep in mind that there is no such a thing like exact tunning of every AY/YM in every Spectrum.
So if the differende on ZX81 isn't close to 1 octave (or bigger) - that's it's pretty good tunning then, hahaha.

[yerzmyey]

-Examples of AY music in assembler, or in BASIC with machine code in REM lines.

I'm not a coder so I can't give You such things but instead
- I can give You AY music with BASIC player (no interrupts) - TAP/SNA
- I can give You AY music with BASIC player+DATA lines (music in interrupts) - TAP/SNA

I can add an MP3 file to let You know how it should sound originally.