Hi all,
I've been working on my homebrew 65c816 computer for a while now and I don't have a good solution for sound generation. I am "cheating" a little by using a propeller 2 for vga generation and thought maybe I could use that.
Thoughts?
( The ay-3-8910 is a option but I'm not sure about the bc1 and 2 signals)
Thanks!

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It takes a truly intelligent person to know that there's always more to learn
Kuzai Longmane (They/Them)

i mean the options are the same as for any other retro CPU like the Z80, 6502, etc.

you could for example go with the SN76489's (or 2 for stereo). each of those gives you 3 square wave and 1 noise channel. it's a very simple chip, so interfacing with it should be easy.
or, if you want something more fancy you could use a YM3812 (+YM3014B), there is a sound card for the BBC Micro based on the YM3812, so you could use that as a reference for your own design: https://github.com/JudgeBeeb/BeebOPL

(Welcome, Kuzailongmane!)

Using a sound chip, or using a microcontroller, both are valid choices. Be sure to have fun! And if you can share your work, so much the better.

Thank you, and i am having fun! hopefully soon i'll just get the project in a (virtually ) working MPC system


would you like to the the schematics i have for it so far?

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It takes a truly intelligent person to know that there's always more to learn
Kuzai Longmane (They/Them)

If you choose to go with the SN76489 be aware that i's rather slow and won't keep up with anything going faster than about 1MHz. However, you can buffer it with a latch to give it time to get it's act together. See the attached schematic.

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Bill

Hm, this poses a problem as i am running my system at 10MHz. ;(
i think i'm going to end up moving to the AY-3-8910.
it that compatible at 10MHz?

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It takes a truly intelligent person to know that there's always more to learn
Kuzai Longmane (They/Them)

Not sure - I don't think so, but the circuit I showed was tested to 14MHz. I did check out the GI chip's data and chose the TI instead. Can't quite remember why. I still have a couple of those around, but I'd have to dig into the data sheet to see why I rejected it. It's big - that may be one reason.

For the circuit I posted you place the data in the latch, then enable the SG and allow it to do it's thing (wait for it to compete the instruction load and execute it .. see the spec sheet) before giving it more data.

The latch and the SG are at two different locations (I put mine at consecutive locations).

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Bill

The latch and the SG are at two different locations (I put mine at consecutive locations).
^
|

is this just A0 connected to an inverted on one CS and connected direly on the other CS?

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It takes a truly intelligent person to know that there's always more to learn
Kuzai Longmane (They/Them)

Yeah, something like this:





In my particular implementation the device select lines were already decoded.

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Bill

I'm doing the same thing with my systems dual IRQ controllers:

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It takes a truly intelligent person to know that there's always more to learn
Kuzai Longmane (They/Them)

The Mockingboard for the Apple II used the AY-3-8910/3 and connected it through a 6522 so it's not exposed to the timings of the main bus. That's how I'm planning on adding YM2149s to my build at some point.

If you're using the P2 then I would love to learn how you have interfaced that. I have a P2 dev board and considered using it as well but the idea of soldering the P2 is difficult for hobbyists.

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Cat; the other white meat.