Original style consoles also have two front-mounted memory card slots for the system's proprietary Memory Unit. These can be used to transfer profile and game data from one Xbox 360 to another. Memory Units up to 512 MB are available from Microsoft. The "Arcade" model formerly came with a 256 MB Memory Unit, but with the Jasper motherboard revision of September 2008, the "Arcade" model began to include 256 MB of built-in flash memory. This was later increased to 512 MB. The memory card slots were replaced with USB ports on the newer Xbox 360 S models.