Abstract: Design?a foundation of software engineering?has its own base of theory originating in architecture and spanning diverse disciplines. The paths of software and design theory separated when software design aligned with the engineering and production metaphors in the interests of manageability and formalism. The two disciplines have continued independent discourses, despite some important similarities. However, economic pressures and technology convergence may be forcing a reconciliation of sorts. As software becomes a pervasive design fabric, designers working in a range of media will converge, and from a systems perspective, lightweight development paradigms appear to be challenging the overheads of incumbent process-intensive engineering models. It is timely to go back to the point of divergence to see just how far modern software design norms have strayed from basic design theory of several decades ago. This paper examines Mayall's 'Principles in Design' (1979) and presents an interpretation of how contemporary software design relates to this unofficial design canon. Mayall's ten principles are treated as an assessment instrument, to provide a mirror on current attitudes and perceptions of the role of design in software engineering.