GameBase_Atari_7800_2007
GameBase_Atari_7800_2007 : Free Download, Borrow, and Streaming : Internet Archive
These files integrate very nicely with the GameBase Universal Frontend (using GBToolbox.exe).
Available for download at:
https://sourceforge.net/projects/gamebase/files/gamebase/v1.3/
AND, here is a link to an updated version of 7800 ProSystem emulator (version 1.3g).
https://forums.atariage.com/applications/core/interface/file/attachment.php?id=417779
This version works with many controllers. Yay !!!