Just be careful of your card in those readers especially if it was a recent HDi install. Those newer cards can burn out if your not careful as they run at 3.3v rather than 5v. Smargo or the Omnikey's seem to be the safest route.
From everything I can find on the GemPlus Serial they support all ISO7816 cards - Class A, B and C ( 5V, 3V, 1.8V). I think it's mainly the Jay car readers which you need to careful with, they seem to be built on very minimal/crude design and are hard set to 5v.
Are these new HDi cards 45xx.
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