Mouser
www.mouser.com
806-KPPX-3P

http://domino2.kycon.com/Pub_Eng_Draw/KPPX-3P.pdf

These connectors are also used in point of sale equipment to power the 
thermal printers.  Also old early 90s laptop power used by Dell and 
Packard Bell.  The power supply I use with my gray Qube (aka Gateway 
Microserver) says "NCR KCR853 for use with Safari SSL/25 Expansion 
Manager only," 12V @ 5A.  I think it cost me a buck many years ago.

djb