Internal interfaces in Ultrabay Slim- what's the middle one?

[basketb]

Just out of pure boredom I looked inside the empty Ultrabay Slim slot of my T61p and saw three interfaces inside.
The left one is for the existing CD/DVD drives and 2nd HD adapters (both SATA and PATA). The right one is for the extra battery. But what is the middle one for?

Could it be that it will accommodate the new Ultrabay Slim sata devices that were announced for the T/W500s?
(I know, those announcements do not mention the T6x, but the official description of the Ultrabay Slim 2nd HD PATA adapter for the T4x doesn't mention the T6x either and it works without problems in the T6x.)

[RonS]

I'm pretty sure that the ATA and SATA are separate connectors. Plus the battery, that makes three.

[basketb]

Do you mean the PATA 2nd HD adapter and the SATA 2nd HD adapter use different connectors inside the ultrabay slot?

[FRiC]

The middle is for the serial / parallel adapter.

I happen to have some pics in my blog.

I also read about the new SATA HDD adapter, so I really want to know if the serial / parallel adapter will still work with the T400/500.

[basketb]

Thanks for the link. This explains it. Still remains to be seen which ultrabay slim devices are interchangeable between the T6x and new machines.