andymanone

SID/YM Voice Routing to a single Audio channel possible?

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To use the Retrocade in a more flexible way, it´s would be really useful,

to be able to route the voices to a dedicated single Audio channel.

 

e.g.: 

SID-Voice 1 to the left Audio-Out Jack 1

SID-Voice 2 to the right Audio-Out Jack 1

SID-Voice 3 to the left Audio-Out Jack 2

YM-Voice 1 to the right Audio-Out Jack 2

 

 

(The reason for my question is: I wanna route any single voice to an special external filter for more flexibility)

 

Is it possible in any way?

 

Thx in Advance

 

andY

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Andy,

 

Yes, it should be very doable but may take a couple days to write and test the VHDL code to do so. The existing audio mixer code is here:

https://github.com/GadgetFactory/ZPUino-HDL/blob/master/zpu/hdl/zpuino/contrib/zpuino_audiomixer.vhd

 

It is on my to do list to make the audio mixer better, I think we need to turn it into a wishbone peripheral, so we can control it from sketches, and add features such as the ability to control the volume of each channel on each output. I'd also like to see digital effects applied to each output channel as well, but lets start with a wishbone audio mixer with volume control first.

 

Jack.

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Oh, one thing... I just re-read your original post and realized there is a problem. I read it too fast and thought your were asking for a per chip connection to each audio channel... It will take quite a bit more work to route each voice to an independent channel. I'll have to think some more on that one, right now each chip outputs all of the voices mixed together... It is an FPGA so anything is possible, but we don't want to make a huge mess of things...

 

Jack.

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Hi Jack, 

 

okay never mind, 

 

if it´s possible, to route the different Chips to an dedicated Audio-Channel, its just an big useful improvement!

 

And if i´m able to route  one day the separate Chip-Channel to an Audio-Channel it´s would be perfect, but its not my greatest concern...

 

andY

 

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As a starter, I have changed the hardware so that the YM and SID are routed to separate audio outputs in addition to be fed to the mixer.  As soon as I've figured out how to combine the changed bitstream and the sketch binary, I'll make that version available.

 

Jack, do you have plans for the mixer already or can I look at it?  I have never implemented a Wishbone peripheral before and this seems like a simple enough device for learning.

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Hans,

 

It will be my first Wishbone peripheral too. :) I don't think it is too hard, I thought about it last night and think I have a plan for how to make all of the voices selectable on all four outputs. Just need to get the time to work on it now.

 

Jack.

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