The video I found on YT seems to be playing it on an Arduino without issues, as does the old MAME code (and my BBC Micro emulator).
The real HW and according to someone else the latest MAME code causes lots of squeals when playing back.
If I reduce all the energy values by 1, they are reduced and by 2 squeaks and squeals are nearly removed.
I don't know which encoder was used but it seems to have a bug by not detecting encodings that won't play back correctly on original HW.
The talkie library also seems to have a bug as it doesn't reproduce the squeaks although, this may be desired as it should still play back non-clipping encodings correctly as well as supporting correct playback of encodings that would work if the original chip had greater ranges of intermediate values internally.
The video I found on YT seems to be playing it on an Arduino without issues, as does the old MAME code (and my BBC Micro emulator).
The real HW and according to someone else the latest MAME code causes lots of squeals when playing back.
If I reduce all the energy values by 1, they are reduced and by 2 squeaks and squeals are nearly removed.
I don't know which encoder was used but it seems to have a bug by not detecting encodings that won't play back correctly on original HW.
The talkie library also seems to have a bug as it doesn't reproduce the squeaks although, this may be desired as it should still play back non-clipping encodings correctly as well as supporting correct playback of encodings that would work if the original chip had greater ranges of intermediate values internally.