Thanks to a few friends I’ve been able to upgrade my hi-res tester to support the CoCo Max III interface. It is a device similar to the Tandy Hi-res interface, but is triggered differently.
Here is what MAME is doing as of today for the CoCo Max III interface:
| Speed | Start Value | End Value | Length |
| Slow | 67 | 483 | 416 |
| Fast | 67 | 483 | 416 |
After going over the data here is what I am going to change MAME to do:
| Speed | Start Value | End Value | Length |
| Slow | 29 | 243 | 214 |
| Fast | 57 | 486 | 429 |
You can see the new values are nearly the same as the previous values, but I think it is an improvement to use values verified on actual hardware.