Cool.

I remember seeing a schematic for the same idea that used two ferranti zn428e chips. unfortunately at the time, early nineties, the chips were already unobtainable for poor young me.

https://www.youtube.com/watch?v=yFKSqlJej1s

Well it works, but not perfect for now.

Interesting device. What kind of drivers does it need to play stereo? Does it appear as two separate Covox Speech Thing to the software?
I suppose data for left & right are interleaved, so that playing 2x 22050khz signals must require to drive the parallel port @ 44100 for example, which means like 386 processor / 2MB memory minimum hardware requirements...

ultramars wrote on 2022-04-06, 01:12:

Interesting device. What kind of drivers does it need to play stereo? Does it appear as two separate Covox Speech Thing to the software?
I suppose data for left & right are interleaved, so that playing 2x 22050khz signals must require to drive the parallel port @ 44100 for example, which means like 386 processor / 2MB memory minimum hardware requirements...

To send data to a Covox, only one "OUT" instruction is needed.
So, Two covox are Two OUT to Two different LPT Port.

Here, we need:
One OUT for Left
One OUT to switch to right
One OUt to Right
Then One Out to go back to Left

It is totally different 😀

I did not add it to Mod Master as I don't have one.

Next Hardware Revision will:
- omit Switch
- Automatic Detection of Playback / Mono / Stereo / Support Different play methods for Stereo Mode (IPlay / Crystal Dreams etc.)
- up to 32Khz per Channel in Stereo
- up to 64Khz Mono

it's great to be able to play stéréo covox without the need of two parallel ports, but i still don't understand which software can make use of this device :p

Can this be used with fast tracker for example, since it can drive 2 x covox, or is it only working with certain games?

it works with all sorts of Covox Software. Except Dual LPT Port Stereo Mode.

There is a lot of Software Supporting Stereo on 1.
This Supports multiple methods of Stereo on 1 Playback.