Bitcoin mining began with computer processing units (CPUs), and then evolved to use graphics processing units (GPUs), but with the exponential rise of Bitcoin mining difficulty, the only profitable way to mine Bitcoin is with Application Specific Integrated Circuits (ASICs).
Mining actually involves the solving of cryptographic puzzles — in the case of Bitcoin, highly complex puzzles that require a lot of computing power. However, it is technically possible to mine Bitcoin with anything that has processing power, as Ken Shirriff has proven. Shirriff has mined Bitcoin with an Apollo Guidance Computer from the 1960s, a 55-year-old IBM punch card computer, a Xerox computer from the 1970s, and even by hand.
If you really wanted, there are other exotic ways to mine Bitcoin, such as with human breath and body heat. All of this will be explored in this article.
Bitcoin mining with a 1960s computer
On July 21 1969 Neil Armstrong and Buzz Aldrin became the first humans to walk on the Moon as part of the Apollo 11 mission. The Apollo Guidance Computer was installed on both the command module and lunar modules during this mission, and all other Apollo missions. It weighs 70 pounds and is under a cubic foot in size, during an era when computers were typically the size of refrigerators or even filled rooms. This made the Apollo Guidance Computer weaker than other computers at the time, but the important thing is it was small enough to fly onboard a spaceship. It has 2.048 MHz of processing power and 4 KB of RAM, as opposed to a 2010 iMac which has 3 GHz of processing power and 8 GB of RAM.
Shirriff went through the complex process of coding up a Bitcoin mining program on the Apollo Guidance Computer. This was an extremely difficult task since the machine is 15-bit, while Bitcoin’s SHA-256 mining algorithm is 32-bit. Also, the computer has a pre-set program that is written on ropes of tape fed into the computer, and a new program for Bitcoin mining had to be written on a simulator and fed into the computer.
In the end, Shirriff succeeded, and the Apollo Guidance Computer mined Bitcoin at a rate of 10.3 seconds per hash. Compare this to Bitmain’s Antminer S9 which mines Bitcoin at up to 14 TH/s. This is 1.442 X 10^14 times faster than the 1960s device. Shirriff estimates it would take about 1 billion times the age of the universe for the Apollo Guidance Computer to find a Bitcoin block.
A punch card machine and copy machine
Perhaps even more impressively, Shirriff mined Bitcoin on a 55-year-old IBM punch card computer, specifically the IBM 1401. Shiriff had to create 85 punch cards for a single SHA-256 Bitcoin mining hashing cycle, and the computer was able to generate one hash every 80 seconds, about 8 times slower than the Apollo Guidance Computer. For each hashing round, the punch cards had to be fed back through the machine, making it a difficult physical task, versus modern Bitcoin mining rigs which are essentially plug and play. Shiriff speculates that it would be possible to set up a Bitcoin mining network with an IBM 1009 Data Transmission Unit, which is the size of a refrigerator and sends 300 characters per second over a phone modem to another computer.
Also, Shirriff mined Bitcoin on a Xerox Alto from the 1970s, which has a processing power of 5.88 MHz and 96-512 KB of RAM. This was difficult due to the Xerox Alto using 16-bit instead of 32-bit, and the programming language is BCPL which is obsolete. The Xerox Alto was ultimately able to mine 1.5 hashes per second, much faster than the Apollo Guidance Computer and the IBM 1401, but it would still take the age of the universe to find a Bitcoin block.
Human hash power
Shirriff has also experimented with mining Bitcoin by hand, and managed to do 1 round of SHA-256 hashing in 16 minutes and 45 seconds. However, a Bitcoin mining hash requires 64 rounds of SHA-256 hashing, so the estimated hash rate when mining Bitcoin by hand is 0.67 hashes per day, and that’s for an expert like Shirriff who knows exactly what do. It is quite complex to do SHA-256 Bitcoin mining by hand, and anyone who is not an expert would likely generate a much smaller hash rate. The complex process of mining Bitcoin by hand can be watched in the below video.
Shirriff is not the only one who has experimented with exotic ways to mine Bitcoin. Max Dovey, a researcher at the Institute of Network Cultures, built a Bitcoin mining rig called Breath that uses breathing to mine Bitcoin. Breath uses a spirometer, a medical tool which measures how much air is inhaled and exhaled by the lungs. The rate of breathing determines the computer’s hash rate, with 1 breath per second generating 1,000 hashes per second. This is notably much faster than the Apollo Guidance Computer, the IBM 1401, and the Xerox Alto, but it is important to note that a modern computer was used for Breath.
Breath generated less than USD 1 of cryptocurrency in several months, and it is more of an artistic exercise to show that Bitcoin mining could be powered by basically anything, rather than a serious way to make money.
Another interesting and exotic way to mine Bitcoin is with human body heat. The Institute of Human Obsolescence hooked up people to special equipment that generates electricity from body heat, and on average 0.6 watts per hour was generated from each person. This is actually less than 1% of the 80 watts per hour generated by an average resting person. Scaling this up, if 44,000 people laid still for an entire month and their heat was harvested, it would generate 1 Bitcoin (at the time).
During this experiment, people who volunteered their body heat received 80% of the cryptocurrency mined. Due to the low energy output, altcoins like Vertcoin and Startcoin were mined instead of Bitcoin. That being said, this experiment started in 2015, and cryptocurrencies have gained tens of thousands of percent of value since then, turning pennies of cryptocurrency into more significant amounts of money.
Shirriff’s experiments with mining Bitcoin by hand, an Apollo Guidance Computer, an old IBM punch card computer, and a Xerox Alto, combined with the experiments which mined Bitcoin from human breath and human body heat, prove that Bitcoin can be mined with literally any device, and powered with literally anything.
Although Bitcoin mining is impractical with weak devices or such low power output, it is perhaps possible to mine low-value alternative cryptocurrencies with such methods, exchange them for Bitcoin satoshis, and perhaps one day those satoshis will become quite valuable.
Image Courtesy: Pixabay