Tried to register on that forum some time ago but never recieved confirmation of some kind. Glad someone else did it.
Maybe we could at least get all the best suggestions in one place what could these be, sources etc.
Track 1: someone made a comment it's a computer game music. I like this theory. Something from first half of 90s.
Track 2: tape noise is obvious on this one, that could be the source. Are there music libraries that were cassette exclusives? VHS? Really hard to pinpoint time of this one.
Track 3: Bit reminiscent of Tangerine Dream, Berlin sound, maybe even US synth/new age pioneers who made lots of cassette only releases.
Track 4: I think there is also a mellotron somewhere in there. Someone kicks a turntable two times throughout the track
Could be a porn soundtrack, no idea.
Track 5: Also a cassette
Track 6: for some reason I think this one is a bit more modern than the other ones
Ones missing are MBV-like interlude which sounds like it is played backwards. Also dissonant noises one which plays after 35000 ft. Pretty sure background noise on that one is a radio or satellite signal transmitting an image or something, used in weather systems.