) The 9600pro is an AGP 3.0 card. It runs in AGP 4x or AGP 8x mode an needs 0.8 or 1.5V AGP voltage.
The BP6 has an AGP 1.0 slot. It works in AGP 1x or AGP 2x mode and delivers 3,3V AGP voltage.
The card would run in a board with the third type of AGP slots, AGP 2.0. That uses AGP 4x, 2x or 1x modes and delivers 1,5V or 3,3V AGP voltage.
The connectors are keyed differently, to prevent damage if the required and the supplied AGP voltage differ. Like with the 9600pro and the BP6.
Here is more on that topic.