Ken Shirriff bought an old Apollo Guidance Computer that NASA used 50 years ago to land on the moon with the Apollo mission. Then he mined Bitcoins - or at least tried: The old computer takes 5.15 seconds for a SHA256 hash. Currently, Miners' Bitcoin network calculates about 65 trillion hashes per second and generates a block of 12.5 bitcoins every ten minutes. The old NASA calculator with its 5 seconds per hash would take a trillion times longer than the age of the universe in today's Bitcoin network to calculate a single bitcoin block. At around $ 140,000 for a block, that makes an hourly wage of far too little.
By the way, Ken Shirriff was the guy who had worked out Bitcoin hashes by hand five years ago on an old IBM1401 mainframe and Xerox Alto.
We’ve been restoring an Apollo Guidance Computer. Now that we have the world’s only working AGC, I decided to write some code for it. Trying to mine Bitcoin on this 1960s computer seemed both pointless and anachronistic, so I had to give it a shot. Implementing the Bitcoin hash algorithm in assembly code on this 15-bit computer was challenging, but I got it to work. Unfortunately, the computer is so slow that it would take about a billion times the age of the universe to successfully mine a Bitcoin block. […]
The Apollo Guidance Computer took 5.15 seconds for one SHA-256 hash. Since Bitcoin uses a double-hash, this results in a hash rate of 10.3 seconds per Bitcoin hash. Currently, the Bitcoin network is performing about 65 EH/s (65 quintillion hashes per second). At this difficulty, it would take the AGC 4×10^23 seconds on average to find a block. Since the universe is only 4.3×10^17 seconds old, it would take the AGC about a billion times the age of the universe to successfully mine a block. […]
To put the AGC’s mining performance in perspective, a USB stick miner performs 130 billion hashes per second.
(source:nerdcore.de)