https://github.com/ayoubserti/node-multi-hashing/blob/master/x11.c https://github.com/ayoubserti/node-multi-hashing/blob/master/x11.h well these are the code for X11 as an example from a node (java) multihahsing library. So if you want to make X11 better start here, if you want to make a new...
I would recommend looking at open source mining software that supports X11 or software you can bake X11 support into, however as X11 is now ASIC based writing software to mine X11 on a CPU or GPU wouldn't be worth the time unless for a hobby. If you are writing code for mining hardware (ASIC)...
also try using a different pool to see if it connects and works. If not it might be old firmware even the latest that doesn't support all mining protocols potentially or needs some proxy inbetween. I haven't personally used one of these before but if you need any help please login to the Dash...