Macintosh security lock

If you hadn't noticed, most (all?) Macintosh models from the first through the Mac IIs had a slot on the back for inserting a security mechanism so that the computer could be chained to a desk. The Macintosh Portable also has this feature. Does anyone know of, or have, an actual locking mechanism that was made for the Macintosh Portable? Actual examples or documentation thereof will suffice if you've got them. Thanks! -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]