The Pella curse tablet is a text written in a distinct Doric Greek idiom, found in Pella, the ancient capital of Macedon, in 1986. Ιt contains a curse or magic spell (Greek: κατάδεσμος, katadesmos) inscribed on a lead scroll, dating to first half of the 4th century BC (circa 375–350 BC). It was published in the Hellenic Dialectology Journal in 1993. It is one of four texts found until today that might represent a local dialectal form of ancient Greek in Macedonia, all of them identifiable as Doric. These confirm that a Doric Greek dialect was spoken in Macedonia, as was previously expected from the West Greek forms of names found in Macedonia. As a result, the Pella curse tablet has been forwarded as an argument that the Ancient Macedonian language was a dialect of North-Western Greek, part of the Doric dialects.
More information on the Wikipedia page [1], with information on the Khiale of Megara, also with text in Doric Greek, at [2]; the page on Doric Greek itself is [3]. There is various other coverage on the internet.