: If you haven't used a CH341A before, navigate to the Drivers/CH341A subfolder in your extracted NeoProgrammer folder and run SETUP.EXE to install the parallel/programming driver.
:
The numbering convention "21019" typically refers to the build version 2.2.0.10.19 or a specific compiled binary dated October 19th. This specific version introduced: neoprogrammer 21019 ch341a link