And which was the oldest and does oldest still work?
Is it a step wise step thing or something else??
The oldest traces back to the CPU/GPU which cost relatively nothing and that was when mining was mostly easy and very rewarding. When you didn’t need to put much in hardware and all you needed was a desktop computer hooked up to a network with electricity and you are good to go.
With over 3 halving a to have occurred and difficulty levels heightened, its only normal that these methods are of no efficiency in today or useless.
Now, you need specialized devices produced to perform powerful computations within seconds from ASIC to come by any luck in mining and even then, it takes time and results depends on how many you can get to operate a mining farm and it’s cost intensive as, you need a lot of power to run them.
The Antminer S1 always had common problems in terms of IPs not found, refusing to boot in low and zero hashrate which did constitute some problems as to why it had to be improved upon or changed.