If this already known I am sorry for wasting your time. Surfing the net I seen a site that said the real xbox mem cards are just usb flash drives with a custom connector.
Soooo when I ordered my yet to installed smartxx chip it came with a xbox to usb cable. And I tested the theory and found out it worked amazing. I turned on the xbox ver 1.3 and went to memory got a warning saying "memory card formatted" I then copied my game saves the first game I tested was PGR-2 which the game box shows memory unit blacked out. I hi lighted the file from the HDD pressed "A" and the next screen had a copy & delete option so I copied it. I started up my new ver 1.6 xbox and went to memory and it showed I had a memory card inserted. Copied the PGR-2 file to it inserted the game disk which mind you was the first time this new xbox ever seen this game. It started up i went to load profile and my file was there I loaded it and it worked like a champ. I went back to the first xbox copied all the game saves from games which the boxes say memory card not supported. And copied them to my new box and all games work and load fine.