Following the prototype of dimonoids, directional algebras are obtained from universal algebras by splitting each fundamental operation into a number of distinct fundamental operations corresponding to directions or selected arguments in the original fundamental operation. Thus dimonoids are directional semigroups, with left- and right-directed multiplications. Directional quasigroups appear in a number of versions, depending on the axiomatization chosen for quasigroups, but this paper concentrates on 4-diquasigroups, which incorporate a left and right quasigroup structure. While introducing several new instances of 4-diquasigroups, including dicores and group-representable diquasigroups, the paper is primarily devoted to the study of undirected replicas of directional binary algebras, dimonoids, digroups, and diquasigroups, where the two directed multiplications are identified. Undirected replicas of diquasigroups are two-sided quasigroups, and thus offer a new approach to the construction of quasigroups of various kinds. [ABSTRACT FROM AUTHOR]