Since official diagrams are unobtainable (Astrosphere closed in 2012), try these avenues:
Because Astrosphere no longer supports this card, many users convert to modern controllers (e.g., Ethernet SmoothStepper). However, the has excellent hardware: astrosphere mcp mb 07241 5 board diagram
To summarize the diagram logic for the : Ethernet SmoothStepper). However