  We survey recent results on the exact dyon spectrum in a class of N=4
supersymmetric string theories, and discuss how the results can be understood
from the macroscopic viewpoint using AdS_2/CFT_1 correspondence. The comparison
between the microscopic and the macroscopic results includes power suppressed
corrections to the entropy, the sign of the index, logarithmic corrections and
also the twisted index measuring the distribution of discrete quantum numbers
among the microstates.
