From Sonic Retro
Segacon is a program created by JJFTails that allows you to "use your PC as a Genesis/Mega Drive controller," as he states it. This program uses a modified version of Mask of Destiny's cord. With this program you can record "Macro Files" or files that store the data of what buttons are pressed within a certain amount of time. You can then play back these "Macro" files in the real hardware. He is also currently working on a way to play .GMV (Genesis Movie Files) files also.