On Apr 6, 17:15, Max Eskin wrote: Even fairly old versions require a maths copro. Some of my then-colleagues at Acorn Computers were involved in negotiations with Autodesk in 1987, to get it ported to the ARM architecture. AD ported Autosketch quite quickly, because it doesn't need a maths copro, but they refused to port AutoCad, because they insisted a maths coprocessor was essential (despite the fact that the software routines available outperformed some contemporary maths processors). -- Pete Peter Turnbull Dept. of Computer Science University of York