Well worth reading:
https://acpc.me/#
Go to the search bar and type Joel - its the only result.
For English speaking readers download the PDF and use Google Translate (Documents) - it does a fair job.
Further Info:
https://cpcrulez.fr/applications_util_comm-amcharge.htm?t=Uw==
https://cpcrulez.fr/applications_util_comm-amcharge.htm
I remember using it several times. My mother had brought home a minitel, which she sometimes used for her work.
And I remember using it on a few Wednesday afternoons to download games to my CPC 6128. :D
It was really, really long...
My earliest memory of downloading with AMCHARGE was the game Operation Wolf.
It was not the full game, but a playable demo with only stage 1.