mining software – Easy to understand simple btc miner?

For study purpose , is there any simple btc miner code that are very easy to understand as long as i understand the concept of btc mining ?

I’ve seen similar question on this website but the answer refers to either a messy code that very hard to understand or an outdated code that does not support the current btc miner protocol (e.g : DiabloMiner) , that’s why i’m asking this.

Any code which last update is behind 2020 i consider as outdated.