A method for implementing a user interface for performing physical design operations on an integrated circuit netlist. The method includes accessing an input file containing identifications of a plurality of blocks of cells of the integrated circuit netlist, each block representing circuit components to be realized in physical form. A view of the plurality blocks is presented to a user, the view provided by a computer display. Attach points are defined for each block. Connections for the blocks are defined by graphically linking the attach points of the respective blocks. The input file is updated in accordance with the defined connections.