1973 Computer Forced to Mine Bitcoin

A group of enthusiasts have managed to get a Xerox Alto computer made in 1973 to work. Not only work but mine bitcoins. The project manager Ken Shirriff was able to use the computer's mining potential, which is 1.5 blocks per second. It involved creating a SHA-256 hash algorithm for the old BCPL programming language.

"At this speed, the extraction of one block on the Xerox Alto will take about 5000 times the age of the universe. The electricity used in the process will cost about 20 quadrillion dollars. And you will get 12.5 bitcoins. Obviously, mining bitcoins on Xerox Alto is far from a profitable business," Ken said.

It should be noted that even for those times the Alto was not a fast computing device. Its speed was about 400 thousand commands per second.

"There was no microprocessor on the Alto arithmetic logic board, instead the processor was built from simple TTL chips. Even for one-bit shifts, eight separate chips are required, so it's no surprise that Alto does not perform more complex shift operations," Ken Shirriff noted.