Implementation of the protocol, generously described here: https://www.triades.net/13-geek/13-serial-protocol-for-a-chinese-rfid-125khz-reader-writer.html
Quick and dirty, don't expect improvements. Should be possible to either modify the script or include it. Works for my black chinesium rfid reader/writer from ebay. It is probably called EM4305 or something like that. It only seems to support 125khz. It does not read empty tags so you may have to write to them first they have never been written to.
No warranty, public domain.