The well-known releases that followed after the duo were signed, first to SKAM and then to Warp Records, which can be purchased in any decent record shop.
The releases which precede this, of which original copies are exceptionally rare. Much of the knowledge we have of the latter is due to The Cosmic Crofter's webpage, which is now defunct.
The exceptions: copies of Boc Maxima and the "Old Tunes" tapes which are almost certainly legitimate are readily available on the p2p networks.
These older items are NOT AVAILABLE; only friends and family of BoC have heard them.
In addition, three extracts of genuine old tracks came from a BoC-related website that no longer exists. They are: "Duffy" (0:24), "Wouldn't You Like To Be Free" (0:56), and "Circle" (0:35). "Duffy" is a gentle and innocent track, similar in theme to "Melissa Juice"; "Wouldn't You Like To Be Free" features massed guitars; "Circle" features slowly-changing high-pitched glacial tones, fitting the Alaskan theme of the album it comes from.
Many albums which purport to be other rare releases are commonplace too, but almost without exception, these have proven to be fakes of varying qualities so far.
Among the fakes, the most common are "eno test" and "parson", wrongly taken to be by Marumari and BoC, whereas they are by Marumari alone. A few other such mis-labelled tracks go around from time to time.
Other fakes include a longer version of "circle" which sounds nothing like the genuine short extract. "trillions" (3:31) is a fake, as is "treeline" '(1:12).
We've been told that these are mislabeled tracks by CiM "nskino" is really "disco alta", "rhomboid" is really isempty'", and so on (thanks, MCBPete). With any luck, the fakes will eventually stop being labelled as BoC.
Boards of Canada's old website disappeared in 2000. Some fans managed to capture music loops that played on the site, many of which were simply Boards of Canada fiddling around, but some early works later became full songs. A 15 minute YouTube video surfaced on August 1st, 2011, containing all the loops on the site, and is embedded below.