So Retro

We challenged John Knight to relive the entirety of computing history through open source. He almost died trying…

- John Knight

Never heard of emulation? It’s when a piece of software mimics another machine in order to run its programs. For instance, you may have seen someone playing old Nintendo games on an Android phone. Emulation is best known for its use in playing old video games on modern systems, but it’s also used in many areas of computing, with many different purposes.

The first emulator was developed by IBM in 1965, for the System/360 line. It could run programs written for the older 7070 system and was a hit with customers. Although emulation would continue to develop in the computing industry, it remained relatively niche until the ’90s, when game console emulation on PCs resulted in landmark court cases. Nowadays emulation is entirely mainstream and is used for everything from virtual machines to nostalgic consoles, like the Nintendo Classic Mini.

Emulators can be described as having anything from low-level to high-level emulation. The lower the level, the closer it is to the hardware, and the more system functions it tries to replicate. The higher the level of emulation, the more it simply mimics the required output behavior (for instance, ‘open a file’ or ‘draw a rectangle on screen’).

There’s a trade-off between speed and accuracy. The more it emulates the original machine, the more accurate the program’s behavior, but at a cost of speed, as your computer has more to process. The higher the level of emulation, the better the performance will be, as your computer can use its own hardware more, but at a cost of accuracy. The program will be more prone to errors and feel less like the machine being imitated and more like the system, it’s actually running on.