Retail Terminal with NO Windows

By now you've likely heard of the next break, this time KMart, the biggest yet. How did they do it? A virus in MS Windows, AGAIN! KMart says the virus could not be detected with today's tools.

Sadly one of my customers used to make the premier software for credit card (etc) processing for retailers on IBM i was been purchased a couple years ago. The new owners are phasing out the IBM i software (because they can't spell i) and is asking their customers to move to their Windows platform instead. Needless to say asking IBM i customers to move their CC processing to Windows is falling over like me in a ballet.

But no matter where the processing of the cards is handled between the vendor and the baks most (all??) retailers seem to have Windows at the point where the customer (and their card) interface to the retailer. This is where the card data has been stolen. Worse it appears most retailers are still using XP (You know the one that's no longer supported!) [Yes I am aware of extended support for XP for retail.]

So my question is could you, would you, create a retail terminal that does NOT use Windows? Could you do it with IBM i? Or have you already done so!?