It possible to hard fork a private network without resyncing chain from scratch?

I am able to hard fork my private chain into first Constantinople and than to Istanbul, please see the answer for it. My approach is: I have updated geth to its highest version I have kept the go-ethereum/params/config.go file as it is I have updated the genesis.json file by adding “constantinopleBlock”: 2862930, “petersburgBlock”: 2862930, and…

Is it possible to mine bitcoins faster on CPUs with this strategy?

This guy on bitcointalk.org suggested a potentially faster method for mining bitcoins using CPUs: https://bitcointalk.org/index.php?topic=265759.0 To quote from the author: “Rather than computationally solving for SHA256(SHA256(block_header)), the approach is to solve it symbolically. What I mean by this is, rather than treating the block header input bits as 0 or 1, treat each input bit…

Getting TypeError: “send” and “transfer” are only available for objects of type “address payable”, not “address”

Working on this Udemy course for Ethereum and i keep getting the error mentioned in the title of the question. For reference i have checked out the answers on questions: 1, 2 and 3. But the error persists. The contract goes like this: pragma solidity >=0.4.22 <0.6.0; contract Lottery { address public manager; address[] public…

Crawl CryptoKitties Javasscripts

We are investigating the off-chain part of CryptoKitties, more specifically, the Javascript code used/referenced in https://www.cryptokitties.co/. Comparing to smart contracts (which are made open-source), the off-chain Javascript is not immediately available. The problem here is how to collect all javascript used in https://www.cryptokitties.co/. Javascript functions are invoked/referenced from different sources like html, another javascript. Particularly,…