  We give a unified description of self-dual SU(2) gauge fields on tori of size
lt x ls^3 based on a mixture of analytical and numerical methods using the Nahm
transformation, extended to the case of twisted boundary conditions. We show
how torus calorons (lt/ls small) are Nahm dual to the torus instantons (lt/ls
large). Holonomies are dual to the locations of constituents, this duality
becoming exact in the limiting cases ls or lt --> infinity. Implications for
the moduli spaces are discussed.
