This is the part that gets missed. A coin's source and binaries are easy to keep; GitHub, Software Heritage and a dozen forks already hold most of them. What disappears is everything else, and it disappears in a
predictable order.
I can give one case from the inside. Blazecoin (BLZ) launched on this forum in May 2014, scrypt PoW. Over the years it lost, one by one:
- its exchange: Cryptopia, hacked and closed in 2019, taking the order books and trade history with it
- its explorers: Cryptopia's and cryptoID's both went dark ("blockchain unknown")
- its market record: CoinMarketCap marked it untracked, so the price history stopped
The only reason it isn't a museum piece now is that the
chain itself never stopped. A handful of nodes kept making blocks, so this year it could be rebuilt on Bitcoin Core 28 with the full history intact,
block 1 to block 4.3 million. The old market history, meanwhile, had to be pieced back together from the Wayback Machine, which turned out to be the best crypto museum we already have.
So if anyone builds this, I'd put these in each exhibit, roughly in order of how fast they vanish:
- a dated copy of the chain data with its tip height and hash (the thing you can't recreate)
- the last working binaries for each OS, and the compiler and dependencies they need, since 2014 code rarely builds today
- explorer and exchange pages, saved to the Wayback Machine while they still load
- the original ANN thread and whitepaper
solarsurfer, I'd be interested in how you approached the auxpow conversions while keeping the chain as it was. That's the one change that would let modern scrypt rigs keep merge-mining LTC and DOGE and still secure
a small old chain. If a complete BLZ chain is useful for your collection, I'm happy to provide a dated snapshot.