My ZX81 saves data to my iPhone (through a Sony NetMD MiniDisc for amplification).
These files played back to the ZX81 is loaded without problem.
I convert these .m4a to .wav on my Mac.
I have tried every WAV2P-program I have found, but they all show BASIC-garbage when it has been converted.
I have tried
- EightyOne Wav-loader
- zx81stuff.co.uk Java tape converter
- zxprojects.com zx81util