Yep, it sure does. From the Yaesu website:
http://www.yaesu.com/amateur/ft847tx.html"* High-Speed Direct Computer Control Interfacing
Yaesu's CAT System for Computer Aided Transceiver control is provided via a rear-panel "DB-9" connector, and it includes a built-in RS-232C level converter. Just hook up your serial data cable, and you're ready for action! Data may be transferred at speeds of 4800, 9600, or even 57600 bps!"
I can also say as an owner of one that it does, in fact, have one <g>