Ahh yes this was for a custom ethernet dongle methinks. It was couple of extra pins next to the main USB-C connector (a 2019 machine, so hardly ancient)
My 2016 ThinkPad Yoga X1 had a custom very thin connector for a propriatory dock or Ethernet dongle. The actual Ethernet chip and MAC address were inside the machine but the chassis too thin for a normal RJ45.
There were a few types of this in the years before USB-C was adopted everywhere by Lenovo (late 2016?); searching online found this, perhaps your was
this one. My Yoga's adaptor looked similar but the PC end was wider and thinner.
I do remember fondly the old-style 'proper' docking stations; 2 rows of parallel connectors and a locking pin at either end. This mated to the underside of the laptop chassis. They worked quite well and as I recall some of them you could lock the laptop into the dock with a key. The dock then being secured with a regular Kensington style cord.
Last one of those I had paid for was for a T40p which was a Pentium M machine; late Win2000, early XP days. Friends whom have Dell machines from work had them for a lot longer.
I always thought a damp desk (or meal tray on a train, or airline) would short out the connector!
25 years of broadband connectivity since Sep 1999 trial - Live BQM
Edited by jchamier (Sun 15-Dec-24 15:27:07)