Plugs let you adapt any FireWire 400 connection to new MacBook

Synchrotech’s 6F to 9M adapter plugs
(http://www.synchrotech.com/product-1394/firewire-400-800-cables-connectors_01.html#CAB-FW8-6-9-CONV)
plugs let you deploy existing FireWire 400 devices and cables with
Apple’s new MacBook Pro computers. Rather than purchasing new six to
nine pin cables to accommodate the new laptop’s single high
performance FireWire 800 port, the adapter is designed to protect
existing investments in FireWire 400 peripherals and cables.

The 6F to 9M adapter allows for full 400Mbps operation. The device’s
part number is CAB-FW8-6-9-CONV, and it retails for US$9.