Proof of Work - An interview with Jan Čapek (Slushpool, BraiinsOS)

## Proof of Work Podcast with Jan Čapek: A Summary

This podcast episode, "Proof of Work," features an in-depth interview with Jan Čapek, co-founder of Slushpool and developer of BraiinsOS. The conversation spans his early computing experiences, the evolution of Bitcoin mining, and the ongoing battle for open-source hardware control. Jan’s personal journey began in communist Czechoslovakia, where he learned programming fundamentals like BASIC and C, fueled by a desire to create and overcome technological limitations. He later joined Slushpool in 2013, helping to stabilize the pool and build trust through transparency initiatives like "Hash Rate Proof." The discussion culminates in a look at BraiinsOS, an open-source Linux distribution for mining, and the challenges posed by hardware manufacturers like Bitmain who are increasingly locking down their devices.

The interview highlights the early days of computing and the internet's transformative impact on access to information. Jan recounts his initial struggles with limited resources, transitioning to the excitement of Linux and the early days of Bitcoin mining, where pools were often unreliable and prone to manipulation. The conversation then delves into the crucial role of trust and transparency in the cryptocurrency space, particularly regarding hash rate reporting and the need for exchanges to provide proof of funds. Finally, the discussion focuses on BraiinsOS and the ongoing effort to create an open-source alternative to proprietary mining firmware, emphasizing the importance of user control and energy efficiency.

Jan’s experiences underscore the evolution of the cryptocurrency landscape, from a community-driven, open-source ethos to a more commercially driven environment where hardware manufacturers are increasingly restricting user freedom. The interview serves as a reminder of the importance of maintaining a commitment to transparency, open-source development, and user empowerment within the Bitcoin ecosystem.

1. Main Topics Discussed:

• Early Computing & Programming: Jan's experiences with early computers (ZX Spectrum, 386 PC), learning BASIC, Pascal, and C, and his introduction to Linux.
• Slushpool's Origins & Operation: Joining Slushpool in 2013, stabilizing the pool, pooled mining explained, competition among pools, and the implementation of "Hash Rate Proof" for transparency.
• Trust & Transparency in Cryptocurrency: The importance of trust and reputation, the need for exchanges to provide proof of funds, and Jan’s negative experience with an exchange.
• BraiinsOS & Open Source Mining: Developing an open-source Linux distribution for mining, focusing initially on the S9 ASIC miner.
• AC Boost Feature & Bitmain's Response: Discovering and publishing a report on the S9's hidden "AC boost" feature, Bitmain's subsequent firmware update, and the ongoing effort to create an open-source FPGA replacement.
• Hardware Locking & Restrictions: Bitmain's hardware locking strategies with the S15 miners, including firmware signing and disabling SSH access.
• Energy Efficiency & Optimization: Concerns about energy waste and the potential for optimization through open-source firmware.

2. Key Quotes:

• "I was so pissed but the thing is since I couldn't play the games I had to learn like the programming part." (On being forced to learn programming due to hardware limitations)
• "Once you get the internet you get the source of the information and then once you get to the university the information exchange so it was so much easier." (On the transformative impact of the internet)
• "Whatever we publish I want this to reflect the technical state of things again." (Jan’s commitment to transparency in reporting)

3. People Mentioned:

• Jan Čapek (Slushpool, BraiinsOS) - Interviewee
• Thomas Hunt (Podcast Host)
• Pavel (Jan’s partner, involved in Slushpool)
• Slosh (Founder of Slushpool)
• Older brother (Jan's brother helped him with early programming)

4. Bitcoin Price/Metrics Mentioned:

• Difficulty of Bitcoin mining was discussed as a key factor.
• A discrepancy in price on an exchange involving Namecoin was referenced.