During the last years, the bitcoin mining turned out to be a huge economic sector. At present, there are also specialized integrated circuits (ASIC) organized for this purpose, more powerful than previously used central processing units (CPU). Nowadays, the mining of digital currency on outdated computers is not effective, and the chances of getting a reward are too slim, but there are enthusiasts who make for it for the sake of experiment or out of interest.

One of such enthusiasts is Ken Shiriff who added a character of bitcoin to the system of Unicode symbols. Not long ago he renovated the Xerox Alto computer developed in the 1970s, where he managed to launch mining with speed of 1.5 hash per second. As he declared, although the process was possible, the Alto power was so low that it would have demanded much more time to get the unit than the universe existed.

One more project of Shiriff, on which he has already worked in 2015, is a mining through the 55-year-old IBM 1401 computer with speed of 80 seconds per one hash. He noted for comparison, that modern equipment could produce billions of hashes per a second, the 1401 computer needs 80 seconds to compute one hash, that clearly demonstrated how much the effectiveness of computers had increased over the past decades.

The next extremely slow miner was created in 2013, with a help of the Nintendo Entertainment System gaming machine of 1985 (NES) with Internet connection and a usage of the Raspberry Pi computer which gets data fragments, compiles them in ROM including the SHA algorithm and current target data, and sents them to the USB CopyNES console. While every ROM computes and tests a single hash.

Experimenters move forward and also discuss the possibility of mining with the help of other game consoles, in particular, Playstation 3.