I’ve been interested in the design and implementation of virtual machines since encountering the source code for a simple Forth interpreter written in Basic when I was 15. It was a fascinating, inscrutable piece of magic which played a key role in my becoming a professional programmer. Most of us who've played games or worked in any one of a number of popular programming languages will have used virtual machines but unless we've taken a course in programming language design we probably have only a loose idea of what these are and how they work. In this workshop we'll look at the various parts necessary to model a computer-like machine in code, borrowing ideas as we go from real-world hardware design. We'll use a mixture of C and Go as our modelling languages: C is the lingua franca of the VM world whilst Go has excellent tooling and concurrency. We'll also examine some of the benefits of phrasing software development problems in mechanistic terms. These include ease of composition, automation, security, testing, repeatability and reasoning about performance. You'll need a laptop with Go and a recent version of Clang or GCC installed and a basic grasp of Go.