Quick AD&D and 2E ruleset questions?

[Filthbeard]

I want to buy and run the B1: Keep on the Borderlands module, but which says 1E on it. I can't find a 1E ruleset for sale though, is the 2E PH, MM, DMG what is used to run B1?
I only played AD&D and then 3.5e, and now 5e. Is the 2E ruleset the same or close to the original AD&D set at least in FG?

[Fear Grounds]

In general terms, 1E and 2E, are functionally the same. Anything made for 1E works in 2E, as 2E was designed with backward compatibility in mind.

To answer your question: Use the 2E PH, MM, and DMG to run the B1 adventure.

[Filthbeard]

Awesome, thank you very much!

[Fear Grounds]

You are quite welcome. Have Fun!