Use my Cingular Motorola Sim in my Ebay purchased locked AT&T iPhone

[ggushee]

I just purchased a LOCKED AT&T/Cingular iPhone. I thought that since i already had a cingular motorola razor that i would just remove the sim and place it in the iPhone. I am now learning that i may have assumed wrong. I NEED HELP. Gordon
Please email me at ggushee@yahoo.com

 

[zap2]

Maybe call AT&T up, and ask for an SIM card that works with the iPhone....

 

[ggushee]

64k Smart Chip in my Motorla

So is it true that the 64k Smart Chip will not work in the iPhone?