Use Family BASIC v3.0. Here are .vtp files (usable in VirtuaNES and Nestopia, though Nestopia looks for .tp instead):
Here's the VTP I converted from the .wav. I'm not entirely sure it's 100% correct (though obviously it loads without issue), since I cut out the voices and I'm not sure what the "SKIP" messages are for, but with the uncompressed WAV file at least we can try again if needed.
FamilyBASIC-Sample3-fromtape.vtp
Accordingly, once loaded, I re-saved it from within Family BASIC to get a direct, new VTP file:
FamilyBASIC-Sample3-resave.vtp
Notably this one's a lot smaller than the original and seems to mostly resemble the second, final segment. I'm not sure what the first ones are for.
For anyone who wants to try this disaster for themselves:
- Open the original audio in Audacity
- (?) Strip out the voices by highlighting them and deleting them
- Use Analyze -> Plot Spectrum; I'm not sure where the lowest peak should be but 2035hz seems to be where the VTPs VirtuaNES dumps sit
- Effect -> Change Speed, set a multiplier of ~0.975× or so
- File -> Export Audio, use "Other Uncompressed Formats", then hit Options and choose "RAW (No header)" and "8-bit PCM, unsigned"
- Save as whatever
- Open Family BASIC v3.0 in VirtuaNES (or Nestopia?)
- Type "
LOAD"
- Edit -> ExtDevice -> Tape -> Play, choose the file you saved
- Wait a while for it to finish and say
TAPE STOP. in the emulator and (hopefully)
OK in-game
- Type
LIST to see the code or
RUN to play it
Hopefully with these instructions you, too, can archive and save any weird-ass BASIC programs you find.
I'd like to see if you can play back a VTP by doing the inverse (that is, opening as RAW in Audacity, and playing it back to a real thing) but I still need a Family BASIC keyboard of my own

I should probably get on that.
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(Lv 244 with 229454007 EXP)