I bought a Dreamcast, VGA adapter, Gauntlet Legends disc, and the Happs universal video adapter that takes VGA input and outputs standard or medium resolution. My plan was to put it in my showcase cab that's currently running dedicated Gauntlet Legends with a medium resolution monitor. Unfortunately my monitor has an issue, even after sending the chassis out for repair.
Apart from the monitor problem, I couldn't find an easy way to interface the 49 way joysticks of my showcase cab with the Dreamcast.
Here's the web page that got me interested in the idea in the first place:
http://www.dragonslairfans.com/smfor/index.php?topic=6.0