We're using split second software in a PC attached to an S4 set for time of day timing. My question is: will the PC drive a GAZc525 scoreboard to show net times, and if so how is the scoreboard connected to the PC?

Yes the computer will drive a GAZ scoreboard but you will need a computer or laptop with at least 2 serial ports. You can easily add an additional port by using an inexpensive USB to serial converter; but my preference is to add a pcmcia slot card for the additional serial connection. Check elsewhere on the forum for specific brands/models and that they will work with your flavor operating systems.

As for the cable, it is a simple 9pin to banana, not quite sure of the pin out but it is the normal pins for transmit and ground.

Fred told me an easy way to remember.
Out (3 letters)=pin 3
In (2 letters)=pin 2
Ground= pin 5
So you would need pins 3 and 5 to send data out to the scoreboard.
Tim Maxwell
Chief of Timing-NYSEF Whiteface