'For many years, NES emulators had a method of overclocking where additional scanlines are added for the CPU for each video frame,' byuu tells Ars Technica. To fix this side effect, byuu borrowed a technique from elsewhere in the emulation community. But because the system's games were designed with that particular clock rate in mind, that kind of overclocking has a tendency to speed up the video and audio, too, which can in turn make the games difficult or impossible to play (or even run, in some cases). Today's beefy PCs can of course simulate the SNES' Ricoh 5A22 CPU at a rate much faster than its original 3.58MHz. But in some in-game situations, when the screen got too full of moving sprites, the processor could fail to create the next frame within the 16.66ms window, leading to noticeable display lag. Most SNES games were locked to a 60fps frame rate, and designers of the time tuned their games so the SNES hardware could maintain that frame rate. While bsnes is far from the first SNES emulator to allow for simulated overclocking, it does seem to be the first that does so 'without any framerate or pitch distortion, and without harming compatibility in 99% of games,' as bsnes programmer byuu puts it. That brings us to the latest update for storied, accuracy-obsessed SNES emulator bsnes, which adds the ability to overclock the virtual SNES processor.

But there's also something to the idea that emulators can improve on the original hardware, smoothing problems like frame rate slowdown that plagued the underpowered processors of the day. When it comes to emulator design, there's something to be said for trying to capture the workings of the original system as accurately as possible, warts and all. A stock Gradius III ROM running without slowdown? The new version of bsnes makes it possible.

Snes emulators 2019