Analogue Tones Of A ZX Spectrum Load Set To Ride Again Via Podcast Project

The glory days of audio-cassette loading are set to return in the coming weeks, with retro fans to be treated to a broadcast for them to hit Play and Record to.

Audio cassettes were the medium of choice for software back when Sinclair and Commodore's 8-bit hardware ruled the roost. The floppy disk seemed impossibly glamorous for the average home computer user and code was instead delivered via audio.

While the sound of those files was unintelligible for most, for some enthusiasts it was possible to discern the type of data being loaded. Right up until the all-too-common R Tape Loading Error (which usually seemed to come right at the end of a lengthy period staring at a loading screen).

As well as the ubiquitous audio cassette, programs were distributed on other media. After all, if one could get a sound out of something, one could also have a crack at popping some data on it too.

Back in 1983, Simon Goodwin (formerly of beloved ZX Spectrum magazine Crash and now working in audio technology) was a member of the Radio Wyvern Computer Club team. As an experiment, the radio station had broadcast the analogue loading tones of data and some keen listeners managed to coax the audio into their home computers.

Nearly 40 years on, another attempt to send out software via audio is to be attempted as part of the Radiolab project Mixtape.

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We struggled with making tape-to-tape copying work (of our own BASIC code, of course) so it will be interesting to see how the format survives the codecs and converters of today's digital world.

"It's amazing how well the ZX tape format copes with duff transcription," Goodwin told The Register. "I'm sure results will vary. Psychoacoustic it ain't."

We can imagine some types of compression doing horrible things to the sound, however, it will be a lot of retro fun finding out what works and what doesn't (spoiler: sticking a microphone beside a speaker probably won't do the trick).

The podcast is due to start today, with new episodes dropped weekly detailing the history of the not-so-humble cassette tape. The code itself will turn up in a later episode (accompanied by lots of warning of when those familiar audio tones will start). Goodwin told us: "The live explanation of how to decode ZX files by ear is certainly worth a listen."

His promise of a deep dive into audio and data copy protection sounds worth a download by itself.

As for what the software will actually do, should you manage to get it into a ZX Spectrum (or compatible device), Goodwin was tight-lipped about the cassette-themed animation. He said he wants "those who download it to have the thrill of watching it work. Of course I expect some will post results – the more the merrier." ®