Apollo Guidance Computer Takes on Bitcoin Mining
In a fascinating intersection of history and technology, the Apollo Guidance Computer (AGC), which once directed astronauts to the moon, has found a new claim to fame by attempting to mine Bitcoin. Computer scientist Ken Shirriff recently resurrected this old story, which originally made headlines when he first showcased his project on his blog in July 2019. This endeavor, where Shirriff programmed the AGC to engage in Bitcoin mining, has once again intrigued cryptocurrency enthusiasts online.
The AGC’s Capabilities
The AGC, famous for its role in the Apollo missions, had a remarkable yet modest computing capability for its time, weighing approximately 70 pounds. With a mere 4 kilobytes of RAM and about 36 kilobytes of read-only memory, it could perform around 40,000 additions each second. Although this specific unit never ventured into space, it likely was part of LTA-8—a lunar module test model—before being rescued from a scrapyard in the 1970s. Shirriff, alongside collaborators Mike Stewart, Carl Claunch, and Marc Verdiell of the Curiousmarc YouTube channel, restored it to working order.
Mining Bitcoin with the AGC
Shirriff’s programming involved crafting mining code in AGC assembly language, allowing the computer to perform what it was fundamentally unsuited for: Bitcoin mining. The AGC required an exorbitant 5.15 seconds to compute a single SHA-256 hash, the algorithm that underpins Bitcoin’s mining operations. Consequently, due to Bitcoin’s requirement to hash each block header twice, this translated to approximately 10.3 seconds for every Bitcoin hash. As a demonstration, Shirriff inputted block number 286,819 into the AGC, which successfully replicated the output but, predictably, did not earn any Bitcoin in the process.
Comparative Mining Speeds
The extreme slowness of the Apollo computer’s mining capacities is noteworthy. Shirriff holds other historical computing devices in his collection; for instance, he also managed to mine Bitcoin using an IBM 1401, which took a staggering 80 seconds per hash, and a 1973 Xerox Alto, which humorously managed just 1.5 hashes per second.
The Current Bitcoin Landscape
When Shirriff conducted his tests in 2019, the Bitcoin network was operating at a high of 65 exahashes per second, or 65 quintillion hashes each second. Based on that, he humorously calculated that the AGC would take around 4×10^23 seconds to successfully mine a single block—effectively about a million times the age of the universe. Since then, Bitcoin’s hashrate has dramatically increased, currently recorded at 934 EH/s. Following this path, it now would take the AGC approximately 5.8×10^24 seconds or roughly 13 million times the age of the universe to find a block.
Future of Bitcoin Mining
As the crypto landscape evolves, the upcoming difficulty adjustment is anticipated, with recent analyses revealing a 22.24% rise in hashprice, indicating miners’ earnings have improved significantly. Meanwhile, Bitcoin’s price made headlines by surpassing $81,000, marking an exciting time for an industry that has faced significant challenges throughout the year. However, it is this stark reality of computational demands and rewards that continues to captivate and educate the crypto community.
