http://gamebank.jp/image/432332.jpg
Any shops selling this? I don't think I could begin to navigate this stores site...something tells me they only sell bulk, but I'm not sure...
You can do slomo, save and load games (possibly save states and save files ala battery saves like), and use cheat codes (w/ on/off switch). It's similar to Bung devices of ages ago, but with cheat codes possible, which I don't think any of those devices had.
Also, it can use PAR codes. Was there a Japanese PAR? I never heard of that...
Actually, here's the manufacturer's site:
http://www.gametech.co.jp
-Rob