Back when Radiohead was teasing the announcement of OKNOTOK, its 20th anniversary remaster and rerelease of OK Computer, the band posted a creepy, glitchy video that looked like—and very well may have been—a program running on a ZX Spectrum, an early personal computer that was hugely popular in the UK during the ’80s. As it turns out, that hint was just a warm up for an even wilder Spectrum-related surprise the band had up its sleeve. Purchasers of OKNOTOK’s $130 Boxed Edition received a special cassette tape that includes demos, alternate takes, and audio snippets from the OK Computer sessions. The last two minutes of the tape are nothing but unpleasant digitized screeching, the same kind of noise the ZX Spectrum would decode through its tape-player and turn into a program.
One enterprising Reddit user had a friend run the recording through a 3.5kHz low-pass filter and feed the result into a ZX Spectrum emulation program. The discovered it was indeed a secret computer program that had been embedded into the OK Computer tape. After loading up, it informs you that the band members are “inside your home computer” and dates the program 19th December 1996, dedicated “with all our love.” After that, it plays several minutes of randomized visuals and sound. There’s also a hidden message within the hidden program, blacked out text that reads: “congratulations….you’ve found the secret message syd lives hmmmm. We should get out more.”