1200	 On Reversible Subroutines and Computers that Run Backwards	 A computer design is describe which permits subroutines to be executed backward as well as forward either with their instructions unchanged or replaced with conjugate instructions. It is shown that using this concept a number of new subroutine types can be developed with rather unusual properties. Since these properties are analogous to certain matrix operations a parallel nomenclature is suggested for their classification.
