Timberline Software Corp, Beaverton, Oregon, and Autodesk Inc, Sausolito, California are working on a joint development effort under which Timberline’s new Precision Estimating software will be fully interfaced with Autodesk’s $2,850 AutoCAD computer-aided design program for MS-DOS computers: the interface will enable designs created within AutoCAD to be fed into Timberline’s $990 Precision Estimating system, and is planned to be promoted by both companies.