Developer Ken Shirriff recently conducted an experiment to answer an unusual question: Could an IBM mainframe from the 1960s mine Bitcoin? To find out, he converted the Bitcoin hash algorithm into assembly code for the IBM 1401 and transferred it to punch cards. He then tested it on one of the two working IBM 1401 mainframes at the Computer History Museum in Mountain View, Calif. These systems are so ancient that they don't even have silicon chips; instead, they rely on a different semiconductor called germanium.
Shiriff discovered that it was possible for the machine to mine Bitcoin, but it would take far too long to be useful. He writes, "It turns out that this computer could mine, but so slowly it would take more than the lifetime of the universe to successfully mine a block. While modern hardware can compute billions of hashes per second, the 1401 takes 80 seconds to compute a single hash."