Palm Treo 650 (GSM)

So my sister gave me her old verizon 650. She has no info for it, so how do I tell if it's gsm or cdma?

Also, I had hoped to unlock this and use it with my at&t sim card, but this unit doesn't have the sim card tray, the port has a permanent cover. So this would be a no-go, right?

Any and all comments/suggestions welcome!

Thanks!