The Thomson MO & TO range of computers (ordinateur français) are similar to the Commodore when it comes to handling cassettebased software: the computer expects a TTLlevel data stream to come from the cassette player, not audio.

This presents a barrier to using the computer if you have nothing else but just the computer.

Also, the [PLAY] button on my MO6 has been glued to the cassette player chassis and so is immovable! Even if I did have an original Thomson cassette, or created one from a WAV file, I wouldn't be able to play it anyway.

My guess is that it's a really bad fix for a broken [PLAY] button. Of course, with some care & effort I should be able to repair it properly, but the issue of having to create a tape remains.

There are solutions available such as:

[1] SDLEP a very simple solution using an Arduino & SD card interface
http://dcmoto.free.fr/bricolage/sdlep...

(where LEP = Lecteur Enregistreur de Programmes, i.e. cassette recorder)

[2] External audio interface this converts an audio signal to TTL useful for the MO5 without a Thomson cassette recorder:
http://dcmoto.free.fr/bricolage/inter...

But I figured, in the case of the MO6 with builtin cassette recorder, or LEP, there must be a very simple solution to inject the audio signal (i.e. WAV file being played by another computer) and get the builtin circuitry to do the TTL conversion, rather than reproducing the circuit externally.

This is my thread where this solution is discussed, along with all the great help I received:
https://forum.systemcfg.com/viewtopi...

After much poking & prodding (without a schematic) I settled on injecting the audio to the collector of transistor TK02, using the Amstrad CPC464 implementation as a rough guide ... but it didn't work.

It turns out I was using the wrong K7 file converter ... the TO and MO machines are incompatible and I was using a converter for the TOseries. Duh.

After more discussion, I was pointed to where the schematics & service manuals could be found which confirmed I was on the right path by choosing TK02:
http://dcmoto.free.fr/documentation/i...

When using the correct format WAV file, and with output volume in Audacity set to 50% ... it worked!

I tried two types of WAV file one that was created directly from the original cassette (The Way of the Tiger) and one that was converted from K7 container format (Arkanoid).

Both worked without issue.

MOseries WAV files:
http://dcmoto.free.fr/programmes/_htm...

DCMOK7 utility to convert K7toMOcompatible WAV file:
http://dcmoto.free.fr/emulateur/index...

I drilled a ø6mm hole where the TV modulator would've been, installed a 3.5mm socket and then connected internally via a 3.5mm plug & socket. This is to allow me to quickly remove the top case by unplugging the cable.