ref:
https://www.retrorgb.com/neslcdmod-beta.html
https://forums.nesdev.org/viewtopic.php?t=14626
note: there's also a commercial version of this mod in the link "Hyperkin Hyper Blaster HD"
https://www.staycaffeinated.com/2024/04/26/light-gun-teardown https://www.youtube.com/watch?v=DzIPGpKo3Ag