SliPiFast
Calculate Pi using the rapidly converging Bailey-Borwein-Plouffe formula. Written in Turbo Delphi.
It's converging to the full Extended float precision (i.e. 17 decimals) within only 12 iterations (less than 1ms), so I didn't bother trying to convert the code to assembly as I wouldn't be able to measure how much faster it may be.