Opening the stacks
Opening the stacks
A fundamental computational concept introduced by Babbage allowing a machine to alter its sequence of operations based on tested conditions, enabling universality and dynamic control flow.
2 chapters across 1 book
The chapter traces the evolution of computing machinery from early mechanical devices like Babbage's Analytical Engine, emphasizing the critical innovation of conditional branching, through wartime developments in Britain and the US such as the Colossi and ENIAC. It highlights the parallel yet independent emergence of the stored-program concept, with von Neumann's EDVAC proposal and Alan Turing's theoretical universal machine converging on the idea of unified memory for instructions and data, thereby laying the foundation for modern programmable digital computers.
The chapter details Alan Turing's development of the Automatic Computing Engine (ACE) project, highlighting the technical challenges of designing a universal computing machine with advanced features like conditional branching and optimized instruction handling. It also covers the administrative and financial hurdles faced in securing support and resources, as well as the institutional resistance and organizational inertia at the National Physical Laboratory that hindered practical engineering progress. The narrative contrasts the conservative approach at NPL with the more dynamic and pragmatic computing initiatives at Manchester University, underscoring tensions between theoretical design and practical implementation in early British computing.