After the 1989 Nintendo Game Boy which was used to “mine” Bitcoin, an even older system, a Commodore 64, was modified to carry out this process.
Commodore 64 was released in 1982 by CBM. It has a processor with MOS Technology 6510, which has a frequency of 1.023 MHz, 64 KB of RAM and 20 KB of ROM. It is clear that as far back as 1982 the makers of this system did not have in mind that it would be used to mine a blockchain-based cryptocurrency. However, this became a reality.
The system performance is at 0.3 h/s. However, the modder states that the code is written in C language, i.e. not in a language that is intended for machines. Otherwise, it could offer up to ten times higher performance. Commodore is upgraded with an add-on card called SuperCPU, which increases performance by twenty times. Certainly, none of the above is enough to make a Commodore 64 a viable solution for Bitcoin mining. Unfortunately, it is not as efficient as ASIC miners that reach up to 18 terahash/s.