In this proposal we aim to examine A(BO)Cu4(PO4)4 family of compounds which are possible candidates for a S=1/2 square-lattice antiferromagnets. The prototypical Ba(TiO)Cu4(PO4)4 system has been shown to order in a non-collinear antiferromagnetic structure below 9.5 K. At the same time, the crystal structure is non-centrosymmetric giving rise to a chiral nuclear structure. Heat capacity together with XRD measurements on related compounds have found that the change in chirality is closely linked to a change in the magnetic interactions. The aim of this proposal is to systematically study this effect of chirality on the magnetic structure. To do so, we propose to employ the D1B diffractometer. In addition, we have proposed to systematically study the magnetic fluctuations of this family using IN5 spectrometer (proposal #75643).