A computer engineer and dedicated blogger, Ken Shirriff, went a little nostalgic in his attempts to mine a Bitcoin block, indicates his use of the good old IBM mainframe from the 1960s.
More than an attempt, it was an experiment to study the feasibility of Bitcoin mining operations on vintage machines. Shirriff, as he mentioned in his blog, went through a lot of hardships just to implement SHA-265, Bitcoin’s underlying cryptographic hash function, on an IBM 1401 computer.
“It turns out that this computer could mine,” he said, “but so slowly it would take more than the lifetime of the universe to successfully mine a block.”
Low Hash Speed
The Shirriff’s experiment brought out some interesting polarity between the modern hardware and the IBM 1401 computer. It found that while the modern hardware system can handle a billion of hashes per second, the 1401 IBM took some sluggish 80 seconds to compute a single hash. The reason for such a poor performance was simple: SHA-256 is implemented to operate on 32-bit machines, while the one Shirriff used could only handled 6-bit characters — and didn’t operate the bit operations at all.
“It doesn’t even handle binary arithmetic, using decimal arithmetic instead,” Shirriff stated. “Thus, implementing the algorithm on the 1401 is slow and inconvenient.”
The mainframe however was able to solve a SHA-256 double in 80 seconds. But even these results drew out a scary analysis, saying that it would take 5×10 ^ 14, or 40,000 times the estimated age of the universe to solve a single block of Bitcoin. He added:
“Today you can spend $50 and get a USB stick miner with a custom ASIC integrated circuit. This USB miner performs 3.6 billion hashes per second and uses about 4 watts.”
It was indeed a challenging but interesting project. In the end, it explained that even an old IBM machine was capable to mine the revolutionary currency we know as Bitcoin. As Shirriff thinks, the best use of this old-meet-new method would be ideal if one time travels back to the 1960s. Overall, this experiment, without any applicability in modern times, belongs to a museum.