Combine butter, sugar, and eggs in mixing bowl and beat until fluffy

Combine flour, cream of tartar, baking soda, and salt in a bowl

Add flour mixture to mixing bowl mixture

Mix well

Chill dough for 5-10 minute, then roll into balls of 1" size - or larger, if you like 'em large

Combine sugar and cinnamon, then roll balls into the mixture

Put balls onto ungreased baking sheet

Press balls down slightly with bottom of a glass or something flat

Bake at 350 for 10 minutes or until done