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http://www.litchie.net/apps/dospad.html
You'll find further useful information here:
http://toucharcade.com/2010/10/26/idos/

You'll need to jailbreak, then follow the steps to get dospad working. Since the last posts all seem to be around 2010'ish, it figures you'd have to downgrade your OS first. Of course, currently you'd need to do that anyway, if you wanna jailbreak, seeing as the JB isn't even out yet for 6.1, as you are well aware.

Concerning alternatives, you might be better off on this forum:
http://www.ifans.com/forums/forums/ios-emulators.59/
 
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