in ThinkPad: T61 and pre-2008 T series plus Other Legacy ThinkPads https://forums.lenovo.com/t5/ThinkPad-T61-and-pre-2008-T-series-plus-Other-Legacy-ThinkPads/Mystery-PCIe-slot-on-T61-models/m-p/598621 ThinkPad: T61 and pre-2008 T series plus Other Legacy ThinkPads topics Tue, 22 Nov 2011 10:21:16 +0000 tp08_en <![CDATA[ ]]> https://forums.lenovo.com/topic/findpost/1307/598621/598621 All the documentation for the T61 and T61p models list it as having two PCIe slots, yet there appears to be a third "half height" slot that is never occupied on any of the systems I've worked on. 

 

Here is a photo....