The retro-1620 project provides a web-based emulator and operating environment for the IBM 1620 Model-2 computer system, a transistorized, decimal, variable-field-length machine from the early 1960s. As stated in the project's README, its main goals are to create a web browser-based emulator for the Model 2 variant and to recover as much software for the system as possible. The emulator reproduces the 1620's two-address, memory-to-memory architecture, where instructions are fixed 12-digit sequences consisting of a two-digit operation code, a five-digit P address, and a five-digit Q address or literal value.
Beyond emulation, the project has succeeded in running historical software on the recreated hardware. A comment on the Hacker News post notes that the emulator's author was able to compile and run a 1963 IPL-V compiler and runtime originally developed at the University of Oregon, allowing users to execute this period-correct software directly in a web browser without specialized hardware or complex setup.
Running IPL-V on this emulator is significant because, as another comment observes, while IPL‑V is considered a poor programming language by today's standards, its manual reveals 'the seed of almost every programming language popular today' and notes that IPL (likely IPL‑IV) inspired Lisp. By providing browser‑based access to such influential early software, the retro‑1620 emulator serves as an educational and preservation tool, ensuring that foundational experiments in language design and computer architecture remain accessible to programmers, historians, and enthusiasts.