Mining #Bitcoin on the vintage Xero Alto would take thousands of times the age of the universe to succeed.https://t.co/SXXqo94Utr pic.twitter.com/JK6q0ROEfa

— Ken Shirriff (@kenshirriff) July 2, 2017

Could a 55 year old #IBM mainframe mine #bitcoin? Yes, but very very slowly. http://t.co/N1xLkJ339J pic.twitter.com/Im2YcW18HX

— Ken Shirriff (@kenshirriff) May 23, 2015

I attempt to mine #Bitcoin by hand, doing SHA-256 with pencil and paper. Not practical. http://t.co/0xQS7brSzo pic.twitter.com/2yyjepQ8qP

— Ken Shirriff (@kenshirriff) September 28, 2014

The Apollo Guidance Computer navigated to the moon, but can it mine Bitcoin? I tried it on our working AGC; at 10.3 seconds per hash, it would take a billion times the age of the universe to mine a block. Still faster than mining by hand or punch cards.https://t.co/uGXfDYWAHd pic.twitter.com/6bLpOzAhqK

— Ken Shirriff (@kenshirriff) July 8, 2019