In recent years, bitcoin mining has become a competitive industry within the cryptocurrency economy. There is application-specific integrated circuitry (ASIC) which is far more efficient than standard CPU. Mining the digital currency on older PCs is ineffective and has little chance of getting profit, still there are enthusiasts who want to experiment and see if it works.

Ken Shirriff is well-known in the bitcoin community for his work on getting the bitcoin symbol added to Unicode. Recently Shirriff has been working on restoration of a 1970's Xerox Alto and managed to get the computer to mine bitcoins at 1.5 hashes a second. “I found that although the mining algorithm ran, the Alto was so slow that it would take many times the lifetime of the universe to successfully mine bitcoins,” he said.

Another project Shirriff worked on in 2015 was mining using a 55-year-old IBM 1401 mainframe at 80 seconds per hash. “While modern hardware can compute billions of hashes per second, the 1401 takes 80 seconds to compute a single hash,” noted Shirriff. “This illustrates the improvement of computer performance in the past decades.”

Another project is an incredibly slow miner built in 2013 out of a 1985 Nintendo Entertainment System (NES) that communicated with the network with the use of a Raspberry Pi computer. “The Raspberry Pi gets a chunk of data, compiles it into a ROM that includes the SHA256 algo and current target data, and sends it to the console via USB CopyNES. Each ROM computes and tests a single hash,” the retro miner creator explained.

Experimenters have had great discussions concerning mining bitcoin with other gaming consoles like the Playstation 3.