There have been debates in this forum regarding what the "proper" aspect ratio is on WolfMAME for playing Donkey Kong. The correct answer, for version 0.106, is 16:9. I'll go into details about why:
The initial debate, sparked by Chris, was regarding 8:7 vs 4:3. While I can see where he was coming from with his 8:7 claim, since the original game is based on a 256x224 (8:7) resolution, the problem is that CRT monitors never have truly square pixels. The best way to determine what the "true" aspect ratio is for Donkey Kong is by looking at the monitor used for Donkey Kong machines (Sanyo EZ-20), and then assuming the user will fill the entire screen's space. The screen size on a Sanyo EZ-20 monitor is precisely 15.3"x11.5". This comes out to almost exactly a 4:3 ratio, meaning that if you fill the entire Sanyo EZ-20 available screen space, you will get a 4:3 aspect ratio. So clearly, you should put a 4:3 aspect ratio in the game options, right? Well, not exactly. Putting the game into a 4:3 mode actually displays the picture in a 1:1 display on WolfMAME v1.06. This means that the "height" (in reality the width due to the upright orientation of the DK machine) is being multiplied by a factor of 1.3 repeating. If you work out the math, you come to the answer that the "correct" WolfMAME 0.106 aspect ratio is 16:9.
So, I contend that the proper, "original-like" aspect ratio for WolfMAMEplus v0.106 is 16:9. There is one caveat: Filling the entire Sanyo EZ-20's screen space isn't necessarily the "correct" size to use. Technically, any aspect ratio could be seen on an original machine. This is just assuming that you fill the entire screen's space on your original hardware. I assume most people likely would do this.
