EWM Update: FPS = Frogs Per Second

So here is something funny. I added support for (monochrome) hires graphics to my emulator last week. It worked, but was too slow to play for example Frogger.

I thought my ‘renderer’ was too simple. I’m simply putting pixels on the screen with FillRect(), which SDL maps to OpenGL primitives. So that is a lot of calls. I started writing a little rendering benchmark so that I could establish a baseline performance and then improve on that.

Well, to my surprise things were actually pretty crazy fast. Just 5 milliseconds for a full HGR page refresh.

Turns out that I was doing way too many screen updates and too few instruction executions. The real solution for this is to properly schedule both but for now I simply balanced them a bit more in a way that runs well on my specific development machine.

Video attached of Frogger moving really well. Probably a bunch too fast even.

If you are interested in playing around with my emulator, you can find the project at github.com/st3fan/ewm.


This is a post in the Emulated Woz Machine series. Other posts in this series: