Before the widespread existence of software repositories like CPAN, NPM, and PyPI, developers seeking to reuse an existing algorithm or library of routines would either check books or journals for code, or, they just might post a classified ad:
Request posted in Decuscope 1965, Vol 4/Iss 2
User groups provided catalogues of software, from mathematical algorithms to system utilities to games and demos. Leveraging the user group’s periodicals, developers could post requests for specific examples of code. Or, more frequently, developers would review catalogs for existing solutions. They would contribute by sending their own creations to the group for others to use.
In this article, we will examine how these user groups coordinated development and shared code, how they promoted discoverability of software, and how they attempted to maintain a high bar of quality.
In my post on the Method of Differences, I focused on using the technique to generate mathematical tables. As some readers noted, there are additional and interesting modern applications of the technique. This post will discuss two of them: sequences to functions, a method of analyzing sequences, and strength reduction, a compiler optimization technique.
The “Method of Differences” is a mathematical technique for reducing the computation of polynomials to repeated addition. Once the system is setup, relatively unskilled human computers can populate dense mathematical tables. This is the “difference” in the Charles Babbage’s Difference Engine which aimed to automate the creation and printing of these tables.
Although historians are usually pushed to decide questions of “who was first,” the question of impact is more interesting. Konrad Zuse has a claim to the first computer, the first high-level computer language, and the first European commercial computer sale, but his relative isolation working in Germany in the 30s and 40s limited his visibility and impact. It wasn’t until the 1970s for his innovations to become more widely known. Raúl Rojas has long contributed to the historical appreciation of Zuse and the remarkable modern nature of his machines. This volume collects and makes available in English many of his previous articles on the subject.
