While in the process of setting up MythGame for some NES roms I have, I decided to use FCE Ultra (FCEU) for my emulation needs. It did everything I wanted, however there were a few shortcuts that I used on other emulators that weren't available. Specifically I was looking for shortcuts to switch saves states +/- 1 at a time instead of directly entering the save state (0-9 keys). This way I can use the extra buttons on my gamepads (Logitech Cordless Rumblepad 2) to switch save states.
One of the reasons I love open source software is the ability to change things to work how I want them to. So, below you will find a patch and some patched source code for FCEU v 0.98.12. The patched version lets you press Alt-F5 to select the previous save state and Alt-F7 to select the next save state. In a similar fashion Alt-Shift-F5 will select the previous movie slot and Alt-Shift-F7 will select the next movie slot. Enjoy!
Here is the source code my patch was created against. It is the latest official release for FCEU.
Below is the patch to add the select previous and next state/movie. To differentiate this modified version of FCEU, I changed the usage description to display the version as 0.98.12-mythgame.
To apply the patch, copy the file to fceu_mythgame, cd to that directory and then run the command:
patch -p1 < fceu-0.98.12_to_0.98.12-mythgame.patch
Finally, here is the source code already patched.